Both are from Watchco. Both sell for $150 AU each. On ebay I payed $179.50. For the Speedmaster case back and $41.00 for the Seamaster CB. I think I made out? John Wilson.
It should work fine, but you may also need a dust cover and possibly a different movement ring. I've never tried it, so I'm not sure.Now I should be able to put the new speedy case back on my sapphire speedy with no problems..right? John Wilson.