brake pads won't fit

rebuilt calipers are dirt cheap & reliable. You might go to your parts house & eyeball one of em & compare the piston recess depth to yours. If you do get new ones get ones for a 76 A body (2.75" bore) cuz the more front bias the better (same price too). If you do sand have a method to get em straight, (I'd be leery) & if hand sanding going in a figure eight motion works the best for an even/level cut