Your Albion revolver is well worth repairing. Apex Gun Parts has the parts you require in stock, so check their net site.
As noted by Peter, the Mark III grips have been modified/updated likely in the 1950's. They were made by the firm of Fraser&Glass under a wartime contract and were the standard grip provided to and utilized by RSAF Enfield, Albion and Coventry Gauge & Tool beginning in 1942. The brass i.d. disc is correctly marked for an Enfield made variant as Albion made discs are marked with the Albion Motors "AM" symbol. No big deal--most Albions seem to have lost their original grips years ago during one overhaul or another.
As far as value estimations, let's get back into the real world. The Albion is a desireable variation of the Enfield No. Mark I** pattern revolvers, fetching a quick 250-400 dollars depending on the scarcity of the variation in question. A serious handgun collector I know has just liquidated the eight Albions he possessed and I saw the revolvers move briskly off his table for those prices. The entire lot was sold within two gunshows. It is certainly not a hundred dollar item. Matter of fact, I'd buy every single one I could find at that price and consider myself most fortunate indeed!