Enfield Martini thoughts pls

My local gunshop has a Martini Enfield in stock. The wood is great, the metal is well used. On the right side of the receiver it's well worn and I can just make out 'Enfield 1877'. On the left it has a crown and underneath VR Enfield, 1889, ME 303 ACII. (I realise this means it was converted to 303 in that year with an enfield barrel but I don't know what ACII means). The bore looks sharpish, although the inside is very dirty. On the butt there is a disc with 1, 1899, 2DMA, 361 on it - would this be the unit and if so which one?
I'd appreciate any thoughts!!!
Also - would I be able to fire normal commercial eg privi partizan ammo through it?

Sorry to post it in both Martini and Enfield - but it is both and I suspect the martini forum is hardly ever looked at!

It should be an Artillary Carbine Mk.II. - 21" barrel and fit an 1888 bayonet.