If its real it's one of 47 built in 1997. You should have a plate near the shifter noting it's a limited edition AND there should be paperwork from SLP. ...call SLP. If it's got the plate stating it's a limited edition, it likely is. However, I've now looked at several and none said Comp T/A on the rear, but the rear badging could have been removed by others or added by the previous owner. Rest of it seems right though.
If SLP built it, they have record of it, and if you didn't get the paperwork they might be able to send a new packet to you for a fair price.
As you're not sure what you want to do, I say sell it. If you wanted the thing, you wouldn't be questioning it's future so let someone with a love for the breed and a desire to have one have a crack at it. ...but realize, that engine is well beyond what SLP did to it which lowers the value even if it was installed AND running. Smart money says that engine is out for a reason, and that reason led the previous owner to pass the problem on instead of repair. Non-runners are non-runners, and custom engines are a jumbo can of worms. I would assume it's not salvageable and needs replaced, and likely with a stock LT1, which makes it a regular Trans Am with stickers, and one that doesn't run on top of that. Literally no value other than as a roller. SLP paperwork might help some here, but forget about "top dollar" even if it ran. It's been molested, and at a minimum, the paint isn't perfect.
If you don't have the plate on the center console, there should at least be glue residue where it was if it existed. No plate, no residue, no paperwork? ...clone. whether it is or not.
You're not finding anything on the VIN because these cars are not OEM modifications, they were pulled from the line, built by a 3rd party, then sent to the dealership for sale. The 3rd party (SLP) has the documentation.