I just looked at your photos. They confirm what cosine and I thought it was. Finding an original finish early M2 with the original, nonadjustable bolt is a stroke of luck. If I were you I would be on the lookout for a 1903 front sight with finish that matches your rifle barrel. Lyman 48C sights show up frequently on the auctions and sell in the $150.00 price range. Original finish M2's are scarce. M2's with the early bolt are scarce. M2's with the original bolt numbered to the rifle are not scarce but about half of them I see have mismatched bolts. You were lucky on all three characteristics.