Decades back I had luck on a hogged out hole by grinding a tiny piece of smooth rod that roughly fit the worn space and shaped to keep the bolt immobile. I made it ever so slightly thicker than the material gauge it was going in, and used stout washers to squeeze it in there and make sure nothing moved around.
With access to a welder your idea is way better - other than filling and drilling whole new holes.
\'96SS SOB: SSRI, Herter Tune, Tri-Y II, , 3000 Edge, F/HO bars, METCO extendeds with CV MMC, Bilsteins, currently Vredestein Ultrac Sessanta (315/35 rear). Finally, wait for it... LT-4 knock module!
\'96FWB BUW-Butt Ugly White: PCMPerformance tune, HDFA w/ swissed filter, 1/2 SLP s.s. catback with H- and Flow Super 50s, oem opti rebuilt 3 times, SS Bars, METCO LCA, Airlift 1000, Monroe SS, PowerTrax No-Slip, CTS wheels with +1 rubber. Finally, yes again... LT-4 knock module!