I dont' knwo waht they're worth, Alan- but back in '76 I worked on a few, pretty much just replacing the front sight to allow zero at 50 yards with patched round balls. Those Enfields shot exceptionally well, nice handling and were very accurate with patched balls. Best, of course, were the 3 groove, 3 banders, but the 2 band, 5 groove tapered depth rifling Enfields would hold under 1-1/2" off the bags and 2" offhand at 50.
; I've never seen any of the .58's shoot as well with minnies as we were doing with patched round balls. Even at 100 yards, it was pretty easy to hold less than 2-1/2" for 5. 80 to 100gr. GOEX 2F was the charge, shot dirty, spit patch with .575" RB and .020" denim patch.
: The muzzle needs a gentle radiused crown to load that combination without cutting the patch. A hammer isn't needed, just a good downward whack with the short starter ball, shaft held in the fist works and doesn't deform the ball. One whack only - make it work - 2 whacks will flatten and deform the ball.