There were basically two types of sword in use in the mid-first Century. The older "Mainz" pattern had a blade 20" to 22" long by about 2 1/4" to 3" wide. It was slightly wasp-waisted and had a long point. The newer "Pompeii" type had parallel edges and a short point, and was approximately 2" wide by 16-22" long. (The Fulham sword is apparently a transitional type; parallel edges, 2" wide but flaired slightly at the hilt, with a long point.) Blades were double-edged with a flat diamond cross-section, without grooves or fullers. The hilt was made of wood, bone, or ivory, and the grooved grip was usually hexagonal or octagonal in section. A thin brass plate was set into the bottom of the guard.
Scabbards are made of wood covered with thin leather. Those for Mainz pattern swords were enclosed in a frame of fluted bronze "gutters", with decorated plates on the front. Pompeii type scabbards had chapes and throats of similar construction, but the edge gutters generally did not extend top to bottom. The decoration could be embossed, stamped, punched, or pierced, and frequently the bronze parts were tinned or silvered.
The sword hangs high on the right side on a baldric approximately 1" wide. (The "baldric clasps" shown in modern reconstructions are probably horse harness fittings.) The scabbard has four suspension rings; at the back the baldric forks and is stitched to both rings, but at the front only the top ring is used, the baldric being either sewn to it or fixed with a small buckle. The baldric may be dyed.
Improving the Museum Replicas gladius
The presence of a pommel nut is not incorrect, but if it looks too much like a ground-down cap nut (which it is), it can be further doctored or replaced. Unscrew it with padded pliers to remove the hilt pieces.
Sand the modern finish off the pommel and guard. If the pommel is too large for your tastes, replace it or reduce its size on a lathe, etc. It can have one or more grooves around the middle. The pommel of the Segontium gladius is egg-shaped.
Discard the steel guard plate and replace it with one made of thin brass. Properly this is set into a shallow recess in the bottom of the guard (easily carved out with a dremel tool). The guard can have carved decoration.
The grip can be made into a proper octagonal or hexagonal cross-section very easily with a rasp and a half-round file, then sanded smooth. Optimally, make a new grip of bone (from a pet store) or ivory (fake ivory is very realistic and may be obtained from jewlers).
Oil all the wood parts well with boiled linseed oil (can be mixed 50/50 with turpentine).
Beware; know what you're doing if you plan to alter the blade yourself. It may be very difficult to remove grinder marks, etc. Any competent armorer should be able to make these changes for you inexpensively.
The blade can be narrowed to about 2", and the point shortened by about 1". (Minimum blade length is 16".) The triangular "ricasso" at the top of the blade can be ground off, although the Segontium blade has small rectangular shoulders. Scabbard
Slide off the frame and remove the brass foil (sometimes this is, instead, a usable piece of thin sheet brass). Cut a face plate from sheet brass and decorate as you like, with embossing, engraving, cut-outs, punched designs, repousse, stamping, and tinning or silvering. The frame can be cleaned up a bit, but be careful if you tin or silver it because the joints are soldered. The leather can also be peeled off and replaced with thin vegetable-tanned leather, dyed to whatever color you like. Reassemble the scabbard and secure the frame with small nails at the back (brass escutcheon pins); on the originals these went through the frame and the wood and were clenched over inside the scabbard, but if this sounds too risky, simply place them at the edge of the scabbard, where they will not interfere with the blade. A small brass finial can be soldered to the tip of the scabbard.
Place a metal ring through each suspension loop, soldering them shut for extra strength.
Use good vegetable-tanned leather, 2-6 ounce, for the baldric. It is approximately 1" wide, forked at the back. Stitch it to the two rear rings; at the front either stitch it to the upper ring, or attach a buckle (like those on a lorica) to the ring and just punch holes in the baldric end for adjustability. "Baldric clasps" seen on some reconstructions were apparently horse harness fittings. The baldric may be dyed, or decorated with discs. From qama to gladius
Atlanta Cutlery and other companies sell a big "qama" knife which can be modified into a useable Fulham-type gladius. It requires quite a bit of work, but total cost should be about $50.
The original Fulham gladius blade is 2" wide with parallel straight edges, but flared slightly at the hilt. It is 21" long without the tang, and the point is about 1/3 that length, 7". It is believed to be a transitional type between the older Mainz type (wide, waisted blade with long point) and the newer Pompeii pattern (narrower, parallel edges, short point).
The qama blade is 18"-19" long, 2" wide, with a 6" long point. It has an I-shaped handle of black horn riveted through the flat tang. The scabbard is wood covered with thin black leather, with metal chape and throat.
Start by cutting or drilling out the hilt rivets and removing the grip. (Use the horn for apron terminals, combs, pugio grip, etc.) You gain almost an inch of blade length because the hilt overlapped it; just shine that new bit up. Check to see that the full length of the blade will fit in the scabbard without trouble. If some blade sticks out, either cut it down or dismantle the scabbard and lengthen the cavity.
The tang, as it is, is too wide and short. Either cut it to about 1/4" wide and weld a rod or bolt (headless) to the end, or forge out what's there into the shape you need. Total tang length should be at least 9". Using a bolt or threaded rod allows you to secure the hilt with a nut if you like. All cutting can be done with a hacksaw, saber saw, or dremel tool; it is not high-grade steel!
Now just make a new hilt as described above, and put it on. The original Fulham gladius was missing its hilt, so whether yours resembles a Mainz type or is more like a Pompeii type is up to you.
Remove the metal from the scabbard. The leather can be replaced if you like, and if you feel the wood is too thick, rasp it down some. How you finish the scabbard is also up to you, bearing in mind the general parameters in the Handbook. The original scabbard was of Mainz type, with side gutters extending top to bottom, and at least two embossed plates.