I bought a 70 Boss 302 carb with the same holes and was going to try the Muggy Weld method.
Luckily, before I did, I ran across a guy on EBay that did a decent job of repairing the holes and refinishing the rest of it. No, it wasn't a show quality finish and there were a few minor things I nit-pic'd but, for $250 or so, I was pleasantly surprised...
I think he filled the holes with some kind of 2-part epoxy before the replating...which obviously doesn't match in that area...but I think it's far better than before. Attached is a pic before plating.
Anyway, he said he worked for Pony Carbs in NY before they moved to NM.
He goes by 'carbontooters1' for his EBay ID.
Phil