As far as I know, these venerable old Dianas used leather seals until they went out of production in 1984ish.

Was musing how they might perform with synthetic seals. Badly, I think - the 35 has a 4mm TP and the 50 has a tap. So, like 4mm TP HW35s converted to synthetic, I guess they'd have a slammy shot cycle, but no greater power.

Just wondering if anyone on here has ever encountered a synthetic seal conversion on one of these, and how it performed?