It turned out really well and I'll leave it as it is - it looks like I bought it that way. The finish is smooth and semi-sheen, and now matches the magazine plastic floorplate exactly. There is a slight scuff on the LHS buttstock where I went a bit gung-ho with the first attempts with metho, acetone and the scour pad, but it's very minor.

The finish is the mixture circled on the bottle:

Original busted Talley for reference (the recent one that broke did so in virtually the same place as this. The recent breakage unit was black, hence the colour mismatch now):

Why it didn't break in the skinnier part of the ring I don't know.