"Composite" = auction code for "we know it's a parts gun."
Trapdoor carbines can be tricky. Keys (and this is NOT comprehensive):
1. You MUST. MUST. MUST calibrate your eyes to recognize the proper contour of the nose of the carbine stock in front of the barrel band. Almost no fakers can get it right.
2. You must also be able to eyeball the proper appearance of the muzzle/crown, and the appropriate relationship/appearance of the front sight to the muzzle. Both rifles and carbines had the same width at the muzzle; because the barrels tapered, if a rifle barrel was cut down by 10-ish inches to the 22 inch length of the carbine, it will be wider than appropriate. Then, the front sight will have to have been added and that's also hard for bubba to get right.
3. Swivels on the trigger guard are always wrong. Swivels on the barrel band are wrong with one exception - stacking swivels were present in some of the earliest ("Custer range") carbines.
4. Nearby carbine hits in the SRS are useful.
5. Know which years had no or few carbines produced.
https://www.armscollectors.com/trapdoor/production.html 6. Probably need to get some idea of the sights and their upgrades as well.
7. Prices highly variable. I paid $3K for my Custer era carbine, $1350 for my "upgrades of 1890" carbine.
Best references IMHO are Franca's books and the good folks at the armscollectors trapdoor forum.