I am not knocking Martinis (though I don't care for the liquid kind). The action is derived from the Peabody, but vastly improved. I like the guns and have owned a couple; I consider it the best of the single shot military rifles, much faster to fire and easier to maintain than the various bolt actions and a lot better than the American "trap door" Springfield.
A GOOD Martini action would be well worth converting into a neat sporting rifle, and those .310's by Greener were hard to beat. But I still am not sure a Martini clone from an unknown source is a good basis for an investment.