Transparent caseback compatibility - KS/GS/etc.

[mseamaster]

I found out that there are some cheap casebacks and some expensive ones despite the construction being the same: stainless steel(hopefully 316) and sapphire crystal.

I am wondering how compatible are casebacks on vintage Seikos, and if any new transparent case backs would be compatible.

Personally my reason is that I don't want to use the original caseback because of the medallion deterioration.

Typically a case back for GS/KS goes for 125€ with tax and everything... while cheaper model case backs go for half or less.