Thanks! The "Both units are interchangeable." sentence gives me hope, but now I'm wondering if I'll need one more part (the "black piece" above the DSTs. It may be worth the bid to see if I can make it work, though I'd be happier with a pre-war unit. I don't really "need" the DST, but there's a lot of take up in the single, and that's the thing I'd like to solve. I know the "slot" in the stock will accommodate both triggers. I'll let you all know how it works out.