I just bought an OTIS Buttstock cleaning kit and can't figure out how to get the whole thing in the buttstock compartment.Any suggestions?

You'll probably have to leave the CLP out.....they will go in there without the CLP......doesn't make sense I know. These are now military issue no surprise that there is some flaw in the design - good kit but you'll have to work around that issue.

How 'bout the cable? I can't fit that in either?

I can fit the entire kit in my A1 buttstock and I replaced the small square bottle with a larger bottle of CLP (the tubular 1oz bottle that you get at the gun shops).  I do leave out the bore illumination tool (orange J thingy).  Plus I fit in a half dozen Otis M16 patches.

The cable is put in the pouch first.  Then in the middle (of the cable loop) slide in the CLP bottle.  Then the two brushes (chamber and bore).  In the remaining space you should be able to fit in the other small parts).  Then slide it into the stock (some compression might be required).  The trick is to loop the cable 3 or 4 times (not to many - not too few).  When compressed the cable should be oblong and pretty much fill up the sleeve (and compartment).

Thanks Forest.I was able to fit everything with your method(including square CLP bottle).I did leave out the orange bore illuminator and pipe cleaners not thinking I'll need them.