Hey Marco- IIRC, there have been folks who have used and reported success with dry mount presses (for removing warps). I think that the megabuck "flattener" out there is just a dry mount press turned on end. I have a friend who is a photog who offered to lend me a press and I will report back. I was not aware of the seal release paper and just planned on using a clean sheet of glass on each side of the LP. I plan on trying 170 degrees and moving up in 5 degree increments. If the oven/glass/brick sandwich method works, there is no reason why a dry mount press would not be quicker, easier and more repeatable. Just switch it off and let the LP come back to room temp under pressure. I can't think of a reason why it wouldn't work. Maybe our good buddy Albert will chime in.
what temperature setting for how long?
I've bought a few lp's on ebay, with mostly bad results, but thought this one was more interesting than most. I bought a "sealed" lp of Chopin polonaises from christofori 383, which came pretty warped. I told him about the problem. He responded the same day, saying that (1) since it was sealed he could not know it was warped (seems reasonable) and (2) I should put it in an oven set low for a few minutes (did not say how low or for how long - I guess these recipes necessarily vary according to the strength of the ingredients). My question is what temperature setting for how long do you recommend for Chopin, and how many times do you baste?