Boomer,
Mine appears similar to yours. Down to the screwdriver as the extractor. Mine has a rubber O ring on the muzzle end too, but a 40-65 case instead of your 45-70. Because my roller has a center hammer, it requires me to slip the action down a bit to insert the sleeve.
As for a front sight, I’m using one that was a “+” with an open square center. I ended up cutting off both the top and bottom legs and using the side bars only. Because it clear on top and bottom, I can even do hold overs with a half a bar if needed.
I’m currently working on getting 3 rifles serviceable. Adjusting a gas block and re-sighting in the scope on an AR-10, chronographing .308 & 22LR out of 3 rifles, sighting in 2 rifles - and hopefully spending some time with each, but we’ll see All are supposed to be done this Sunday. But, I am looking forward to spending some quality time with my 22’s in a few weeks!
Oh, and I get you on old eyes too. Previously near sighted with bad astigmatism in both eyes. Corrected with LASIK about 10+ years ago. Now the readers just keep getting stronger, though the great distance vision I once had after LASIK is starting to fade. Currently only my roller is non scoped. For now the front sight with the 30” barrel is still crisp with good light. Dim or evening light not so much...
John
[edit] If memory serves, my sleeve is a David Crossno version and not a Lee Shaver version. If I recall correctly, I bought mine from Buffalo Arms.