I do not have a copy, but I know what you are talking about. I can give you a breif run-down. SFCII/OP models are pretty much ready to go straight into SFCIII. Infact, you need only drop them in the right folder and add the right defaultCore and defaultLoadout entries. However, to make your model work even better in SFCIII, there are a few things you may want to do, all optional, but definite improvements.
1. SFCII/OP Hardpoint weapon assignments are reversed. In SFCII/OP HP's 11 and up are the primary weopons, and HP's 9 and below are heavy weopons. In SFCIII HP's 9 and below are primary weopons and HP's 11 and up are the Heavy weapons. This can be left alone, but that would make the weapons come from the wrong place. Instead, you can import the model into Max or Milkshape and either move the HP's around, or rename them all.
2. SFCII/OP models do not have individual damage textures. These are not nessesary for a SFCIII model (for example, the stock Excelsior class does not have them), but they certainly add to the visuals. It is nothing special to add damage textures, mearly create the textures making sure they are 128x128, 256x256, 512x512, 1024x1024 or any combination and name them same as the model's original textures with a "d" added to the end (no quotes). If they do not seem to work in the game, go into the ship's folder and delete the *.x file and try again.
3. There are 3 bitmaps that are used in the user interface for each ship, the TI, BS, and VL. They are optional if you just want to brute force your way into adding a ship to SFCIII, but you should include these with any release. These can easily be made from screenshots of the ship model and there are some good blanks in directory Assets/Models/ModInfo. You should reference the stock models to get a better idea of what you need to do here.
4. SFCIII is more picky about mesh errors, duplicate polygons, and overlapping geometry. It may not be a big deal to you to have flickering portions of a ship, but this will undoubtably occurr if your mesh is not constructed as a single unit. To better describe it: when you look at the mesh in wireframe mode, you should be able to follow the mesh lines from one vertex to any other vertex on the mesh, always going through a vertex when changing direction, and the model should be such that if you were to fill it with water from one point on the model, the entire model would be filled up. Some SFCII/OP stock models do not meet this criterial, for example the FCX. It is not easy or fun to cure a model of this because it usually involves deleting polygons, replacing them and then remapping the textures. In my opinion, not worth it.
Anything else anyone? Anything I forgot??