I have already removed the cowl vent cleaned it up and painted it, but the pivot points on the brackets attached to the cowl are very hard to rotate. The rust has gotten in between the lever and base. These brackets appear to have a rivet as a pivot. I've got them to move some, but want to free them up so the cowl vent will operate properly without damage to the brackets. I really am trying to avoid breaking the brackets. The hardware I removed were small carriage bolts with flat washers and lock washers. Can't seem to find replacement hardware the same size?