I just purchased a Singer 7-31 and will have it running soon – the table has not arrived yet. This is a real beast of a machine. What do you use for oil? I’m thinking that regular sewing machine oil may be too light and something heavier should be used. I have downloaded the manual and will have it running soon. A leather worker purchased it from the military but he used it very little. It appears to have had little use. It seems to sew pretty well and hasn’t been sitting in a barn, just a little shop dirt from lack of use. It needs adjusting to do long stitches, without making thread nests on the bottom. Any information about oil you use or general problems and adjustments would be greatly appreciated. I too like to repair the old Singer machines. Best regards from Nebraska USA