It's amazing how some people will ruin something or do real botched repairs. I just found a undersized nut wedged in my clutch fork last night so I'll have to take out the clutch and brake pedals to repair it, all because the PO saved the price of a nut and washer.
Are you sure he welded the wiper post or did he braze it? The end of my shaft appears to be brass. If it's brazed you might be able to remove the shaft, heat with a torch, then push a nail thru the hot brazing alloy. You'll have to completely disassemble the unit and carefully remove the shaft from the internal paddle otherwise there is a risk of damaging the paddle which is either leather or rubber. Be very careful with the gasket, they're fragile and almost impossible to get replacements. Or you could carefully drill out the hole. I think you would have to use a drill press with a vise. HLW
