You can sell as a private party now, you just have to pay for the tax stamp. In state/private would just be a Form-4 transfer, so the buyer would pay the $200 tax stamp fee, SOT would facilitate and possibly charge a transfer fee (my local is $50), and that's it. Out of state would be Form-4 + tax stamp back to SOT, Form-3 transfer to buyers SOT, then Form-4 + tax stamp to them, plus any transfer fees.
So not ideal, but not impossible. And as I said, the lifetime purchase idea is a stigma that needs to die. Now with no tax stamp fee if you don't like your can you can list it locally, probably take a $150-200 hit offering to pay for the transfer fee and rid yourself of it, just like a used rifle.