Questions and needing help with NRA (SMRC?) Greener .22 conversion

Good Day,
A few months ago I purchased a Martini Henry rifle that was converted to .22cal by Greener for either the NRA or the Society of Miniature Rifle Society. On the right side it is marked with a navy arms import stamp and:

Queen Victoria cypher (V.R.)
B.S.A & M. Co
1881
III
1

on the left side of the receiver:

Queen Victoria cypher (V.R.)
ENFIELD
1894
MM 303
AC III
(a struck out serial number)

Over stamped on the left side, it is marked

CONVERTED FOR THE N.R.A BY W.W. GREENER

The muzzle end of the rifle clearly shows that the .303 barrel was relined with a .22 sleeve and stamped

PARKER RIFLED AGP

What I would like to do is restore this rifle to shooting condition. The rear sight mounting hole are 3 inches (center to center). The front of the barrel is dovetail cut with the base of the cut being 1 1/8 inches in length. I'd like some help identifying which sights would be appropriate for this configuration and any history out this rifle.

Thank you in advance,
Michael

https://www.milsurps.com/images/impo...1ffbea38-1.jpg
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https://www.milsurps.com/images/impo...572bd7e6-1.jpg
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Good day! I assume you are meaning you want to restore it to shoot .22 as opposed to retrofitting it to shoot .303again? You have a rifle which has been around! It started life in 1881 as a .577/.450 Martini-Henry Mk III, then was arsenal converted in 1894 to a .303 Metford, hence the MM for Martini-Metford. If I recall, the AC stands for Artillery Carbine. Once sold out of service it was sleeved to shoot .22., and probable rebar relied as well as that barrel looks very long for an artillery carbine. I have three of these .22 conversions, and they shoot very nicely. Is the bore good? Given the drill hole in the barrel and the fact the front might is missing, I would suspect this was modified at some point to have a scope sight on it, maybe one of those long eye relief Unertl type scopes. Others may know better. Nice old rifle; should shoot well for you. Ed