Your aftermarket stock sounds like an ATI/Combat Exchange Monte Carlo stock...except for the lack of the spring...or even an access hole to transfer one from your previous stock. That makes me wonder if it is a Butler Creek stock...
I had to use an ATI stock today on a project...and the damn thing fits like a glove...I hate it, but the stupid thing works. I have another that was purchased used out of a barrel using up trade credit at a shop, it is a Combat Exchange...the previous patent holders before ATI bought them out...they are a little shiny vs a matte finish on the ATI. The CE one was mishandled during fitment by the previous owners...and does have a little back and forth slip on it...with a minimum of half a dozen SKSs attempted in it.
If it is a Butler Creek...I would be interested in it...despite being messed up (maybe). I have an affection for aftermarket SKS stuff...and a Butler Creek stock isn't in the collection. Most of said collection does not get used...I dig the wood...but being from Montana I feel remiss in not having a Butler Creek stock...despite not digging the MC stock much.