Anyone have this PH4 rear aperture piece and lenses?

Rick asks (above) about tightening down a thread retainer onto the lens. We used to do it but only (?) when the lens was cushioned - as in the sprung spacer between the lenses and the retainer was brass. If not, then a 1mm thick neoprene O ring will do the trick and probably waterproof it too. Not a bad idea to waterproof the ocular lens of a No32 Mk1 type.

I looked at my odds and ends in the sight spares bin but don't have any filters. I use one of the camera diopter eye pieces with an AJP 5/83 back sight attachment to tighten up groups. When I tested the Criterion sample barrel in a hastily assembled Savage No4Mk.1*, I used one to get the maximum result with handloads and the 174 SMK bullet at 100 yards. I managed to get 1 3/4" five shot groups with it. Considering my eyesight has always been crap, I was quite impressed.