I know this won't help your immediate problem, but I keep three, sometimes four spare SB2 frames. Invariably, a new barrel will fit one of the frames perfectly. At this point, none of my Handis has been shimmed or had metal removed. Yes, they are an investment, but they're like money in the bank and can be sold in our classifieds for whatever they cost. The only big problem with them is they weaken your resistance. Knowing they are there, it's very easy to pick up another barrel. Then, of course you need the scope, the sling, the stock set, ammo or reloading dies, bullets and brass, etc. etc.
Pete