I finally got around to firing this old girl.
I checked it out and all parameters were nominal, so I started out with low power handloads.
It shot well and the ejected brass matched some older brass from a previous No.5 from three decades ago that I still had, awaiting reload.
It seems I need to replace the extractor spring as it lamely spits the rounds out, but springs are easy to come by...all in all, I'm pleased with this cool shooter!
Jim