Hello, first time poster here. I was looking for a replacement crystal gasket for Seiko Speedtimer 6139-7020 and 6139-7010. I have tinkered just enough with these watches to feel comfortable replacing crystal and gaskets on my own. Given that the watch itself is from 1970s, I can understand that the crystal gasket for them are discontinued, but I thought there should be a compatible gasket out there: it has an L-shaped cross section. Otto Frei's store did not have anything compatible with it, and I couldn't find one in hal0eight's ebay store either. I'd really appreciate it if one of the fellow tinkerers can suggest some leads on it.