I've used the glass plate method with only moderate success. On some LPs the bead would heat up and deform enough to allow the glass to contact the grooves before the record would flatten out. This would leave a flat spot in the grooves and ruin the record. I always wondered what would happen if pressure were applied first, but was afraid to try clamping the glass for fear of breaking it. It seems to me the Seal press would be great, as long as you're patient enough to get both the pressure and the temp correct.
As an aside, I had my best results at 200 degrees, and any glass cutter can sand the edges of the glass plates so you don't cut yourself.
As an aside, I had my best results at 200 degrees, and any glass cutter can sand the edges of the glass plates so you don't cut yourself.