well to get you started: open up the set file in a text editor and take a look at it.
You'll have a section called [TILES] and a section called [GROUPS]. Those are I believe the only sections that will change in this merge. You will also need to edit the ITP (palette definitions) using a GFF editor, and I don't have time to explain that to ya right now. Right now just get familiar with the SET file. Read what I ramble on about here. And then get a GFF editor so you can also edit the ITP file.
RAMBLE ABOUT SET FILE STUFF:
As in most computer crap, its all just sequential lists with an index number to keep track of it. TILE1 TILE2 TILE3 … TILE1353 etc… So open the SET file that you want to merge the tiles into. in that file find the end of the tiles list. that is where you will paste the tiles you want to add. its called "appending", adding on to the list. Then you will need to change the numbering of them so that they are sequential. So say the last TILE in the wagon's microset is ID'd 19. The four stomach tiles will need to be added in order 20 21 22 23. Make sure they are just the stomach tiles and not some duplicate tiles in the microset. Then after you have the last tile aded, you need to check the number, and go to the top of the list. At the top is a TILE Count. You'll want to update it. Basically change the number to the last tile in the sequence - 1. It is one less than the ID of the last tile because the count starts at 0. Typical computer crap thing. Counting begins at 0 instead of 1. Its actually a groovy way to count, but takes getting used to.
OK. GROUPS. I forget exactly which tiles are the stomachs, BUT you can find out which ones they are in the stomach SET file. Go to the GROUPS section in that set, and look for the stomach groups. They'll have a group definition and list of tiles, each one with a number of the tile in the stomach SET. Those are the tiles you want to copy. AND you want to copy the group definitions to the other SET file too, but make adjustments like the actual TILE id and group ID and group count etc...
This is a very fast run down. Just start byopening the SET file and looking at it. Much of this might be self-explanatory once you poke around to see for your self how the file is set up.
