Give it a shot of WD40 to stop anymore rust from forming, rust never sleeps, as long as its sharp I wouldn't touch it but if its been rusty for a long time I would sharpen them because the rust may feel sharp but once it starts cutting its going to wear the edge off, when I had my model 30 jiffy I would use my bench mounted belt sander to sharpen the blade, just find out what the angle is and set the table to that angle then screw the blade to a board and sharpen it that way works good to
