pcm with no vin??

[lsxfox]

I just traded my ls foxbody for this 63 nova with a corvette ls1 in it with painless harness and stock ecu.
I have hptuners pro and I have used it before but never had this issue before.
when I go to the editor to connect to the pcm it asks for the vin like always but I don't know the vin and its not pulling it by itself..what simple way can I just put another vin in the pcm to be able to do some tuning in it.
I am unsure of what pcm is in the car, my guess would be from either an 01-02 corvette ls1 but im just going off what engine I have in the car when I got it.
I do not want to take it to the dealer to get them to reflash it to stock with a new vin, and I also only have access to my own hptuners pro software..i either would like to simply put another vin in it or just get a different pcm.

[lsxfox]

also it had been programmed before by a company that also uses hptuners and does not lock their pcm's, I already talked to the guy but didn't understand the steps he told me to do over the phone at all..someone had peeled the barcode off the pcm

[2xLS1]

I've never had HP Tuners editor ask me to enter a VIN#.