The good news:

The GM LRH 1:28 50 cal barrel arrived today.

The bad news:

It's a drop-in for my Cabela's Hawken 54 cal stock, well, almost.

Challenge #1 - The ram rod rib is 1/4" too long and the hawken has a metal end cap, so I'll opt to trim the rib.

Question #1: should I remove the rib or trim it on the barrel? I may be able to slip a piece of paper between the rib and barrel and cut with a hacksaw and/or get nearly through and "tear" or flex it off. I'm concerned about mucking up the rib screws - never had one off.

Challenge #2 - The breech hook of the new barrel is 1mm wider than the tang slot. Mic's identical in all other ways.

Question #2: would you widen the $25 tang slot or narrow the $180 barrel breech hook, keeping in mind if I widen the tang slot the 54 cal barrel will be 1mm smaller than the slot should I choose to use it. Is that a big deal?

I have a good bench vice and numerous files, am a reasonably accomplished craftsman and would like your thoughts.