I finally got to it! Took a great deal of back twisting and one broken drill bit, then finally a reciprocating saw to cut the rivets (since I couldn’t see very well to drill straight through the rivets) but I got the pad plate off. I then did an ugly weld job to fill in the holes, ground them flat, and drilled new holes. Clamped in place, marked new holes on arm, drilled and bolted on with Allen head screws and locking nuts. Moved it about 3/4”-1”. A little more room for my wide numb feet.
1957 Chevy 3200 Daily Driver PS, A/C, Tilt column, Rebuilt 350, Rebuilt TH350, Reupholstered Bench Seat, sound proof/insulated, LED headlights/taillights/backup lights/interior courtesy lights. Follow in the DITY