HW 35 piston dimensions

[MDriskill]

OK, this is kind of a weird request! But if anyone just happens to have an HW 35 piston lying about, I'd be very interested to know how its dimensions compare to this one. It's a leather-sealed one from a gun made in 1980.

Thanks in advance!

[MDriskill]

For the record, I got some interesting replies to this over at a UK forum. Long story short, my piston looks perfectly typical for a leather-sealed gun of its age.

But the following plastic-sealed ones from the 80's and 90's have a slightly shorter rod protrusion, and a slightly thinner seal. So unless there were other internal changes, they would seems to have a longer stroke of maybe 5mm or so.