As I said, considering the rough condition of much of my LP53, 'proper' restoration isn't really a priority for me. I've been rather more cautious with interventions on my 1950's Webleys as they're in much closer to original condition. But with this Walther I'm not worried, it's actually been dropped a number of times, resulting in that barrel shroud crack (actually that one probably came from it being used as a hammer, as there's a deep dent along one edge of the spring cap showing it was smeared against another piece of steel, with force) and broken-off front and rear sights. I've made a new front post and adapted part of a rear sight to what was left of that, then painted the barrel shroud (which was worn down to bare zinc-aluminum casting with little black left) with an epoxy appliance paint, then baked it. The result looks a lot better than it did, but still, this will never be a collector piece.
I happen to have a few dozen 2mm x 6mm O-rings, purchased as spares for my Brocock Atomic. The breech had two O-rings as it came to me, one about 1mm x 8mm, the other seemingly 1.5mm x 6mm, somehow both squashed in and gradually flattened through improper storage - I always store my Webleys breech-open for just this reason and my home made seals last a very long time, then I can make new leather and brass tube seals if ever needed. It turned out the 2x6mm rings fit perfectly. They leave a slight gap around the outside, but the inner seal is the important one and that's perfect, as a tissue lain across the breech when firing does not puff up in the slightest. 'Leonardj', an airgun repairman here in Canada, tells me that it just so happens that 2mm x 6mm is the correct ring, so my experience and his information coincide and it's all good.
Not sure I'd want to shorten the shroud, but I'd like to see that result. What have you used to solder to the aluminum? Seems the rods for low temperature alloys from muggyweld.com would do the job, is that the sort of thing you've used? I'd like to file out then solder along the crack in my pistol's shroud just to have it un-cracked, though it seems not to be a structural problem. But I'm unsure about welding with such a finicky alloy. Comfortable enough brazing with steel, even the odd bit of stainless, but casting alloys tend to turn into a puddle if one isn't careful.
The H&N pellets I have deliver the highest energy so no need to switch I think. They're 4.49mm, which works very well in my Pardini K12 pistol, so I have a fair number on hand, and they're quite a bit lower cost than R10 here.
This is how mine has turned out. I decided last evening to glue on a ring of aluminum around the horribly disfigured end cap. It stiffens the rather soft steel. Might knock that off some day and turn down the ruined knurling and braze on a steel ring, but then again that's a lot of fuss and this aluminum tube section seems to be working nicely. Easy enough to hand tighten, and I've put a large O-ring under it to prevent the bottom plate from rattling a little.
Oh, regarding the two-handed grip and stance... yes, I've tried that, but it seems to go against the grain for me. I'm used to the old-fashioned one-handed planar stance. From 10m AP competition. Shooting two-handed and with my chest facing a target just feels wrong, and the efforts I've made so far using that sort of shooting don't improve groupings at all, just because I'm bad at it. I'll keep working on a firm one-handed grip and see where it gets me.
http://www.luthier.ca/other/forum/LP...3_finished.jpg