I'm having a lot of fun with this and I appreciate all the tips and encouragement. I am still working on the pizza stone experiment. Gofar99's suggestion is working the best so far. I think it helps that the pizza stones are round and the records are round. I decided not to put any more records in the oven. It creates an odor and it probably sets off toxic fumes. We're all still staying at home, and I don't want my kids around that. I also cook with that stove and don't want to jeopardize their health by serving tainted food. So instead of using the oven, I'm using the sun. It's a slow process, but I think that's part of what helps. The record is much flatter and it doesn't look like the grooves have been compromised. I need to stick it back outside again for a little longer once it stops raining. I know you aren't supposed to expose records to the sun, but the pizza slabs are covering it and I extended the silk so no UV rays are shining on the record.
Leot55, I thought about using rice paper but nixed that idea. It might have worked as a decent barrier/protector though. I just didn't want it to get sticky and leave some residue on the record. I also considered using a sheet of latex or just leaving the record in its sleeve, but I used silk instead because it's slow to catch fire and it's slick.