Re: M1 .30 Carbine
J.C. Harrison wrote the best book on the M1 Carbine, it’s a spiral bound book called “Collecting the M1 Carbine”
If the Carbines have original parts on it, the value will be higher, same with the stock if it’s original to the rifle.
What’s really interesting about Harrisons book is there are “correct” Carbines out there with a few mixed parts. If a maker was short on slides or bolts or any particular part, it wasn’t uncommon to have another manufacturer send them the parts needed to complete a shipment.
Short answer is watch Gunbroker and see what they sell for in the similar condition.