Just been shooting my HW55 serial no 878*** which had a leather piston washer fitted so it would appear that whilst the 35 got the nylon washer at the same time as the intro of the 80. The 55 and I suspect the 50 as well continued with the leather washer.

Until when is the next question we need to answer.

Agreed Mick that fellow in AGW this month must be his dad.