Just a quick update. Drilled it out, upset the arbor shoulder and screwed it back in. Was really tight getting it back in and having the wedge slot aligned. Made a new pin out of a steel nail and drove it in. Put a little bluing on the end to blend in with the frame color. The arbor can't move at all now so I call that a success. Found it pretty easy once I got going. All that is left is to address the short arbor. Was already aware of that and have my plan to fix. Going to get a brass washer, easy to file down, and adjust the thickness to fill in the gap. Just going to drop it down the arbor hole in the barrel, not going to bother with JB Welding it in. As long as it fills the space it shouldn't matter.