Actually, replacing the nipple is NOT that big a deal. Certainly, try to match the old one to the nipples at the store. If you had access to a plumber's die set, you could clean up the threads a bit with that. OR, you could just replace the nipple outright. Wrench it out, get a new one that fits the length, apply teflon tape or paste, crank it back in, and finish the 30 minute job six hours later.
Don't you love these challenges??