Looks as if you're getting there - 1.5" is nothing to sneeze at. For 50 and 100m'yds work, you 'll have to get used to 'taking a fine bead', and with some practice, it can be quite accurate - not to mention repeatable. At the start, I was also soundly cursing the crude sights, but it just takes some getting used to them, that's all. But you'll see that a full sight pic will be just about right for 200yds.
Bottom line is - while they are picky about loads and bullets, these old rifles can certainly be made to shoot - and shoot well... to our greater delight, of course!
Added bonus is of course you look really good at the range, everyone wants to have a go at the old warhorse - until they see the rounds, that is!
Now you still have about 4 months left to get ready for the Imperial (hint, hint...), where some of us will do our best to put some martini's at the top end of the 'Vintage Military rifle - Medium calibre" score sheets...