Jessie,
Overall looks to be a good buy. If it is actually marked as a model 500, the screw-in chokes are aftermarket installed. I believe than not until the introduction of the model 505 were factory installed screw chokes available.
The adjustable comb is not original. The Monte-carlo stock is intended to facilitate shooting Trap. I cannot see in the pics if there is a mid-bead which would indicate that the gun was built as a target gun rather than a field model and the MonteCarlo added at some point. SKB did serialize the wood to the frames so if you care to check originality, take off the trigger guard and the number should be impressed in the inletted wood.
Tim.
