I have a couple 100 year old hand planes that I've bought at estate sales. The handles are usually broken in one way or another, so I modeled a set of good handles that can be printed. These are approximate replacements for Bailey (Stanley) hand planes. They should work for any size, but this one came off a #5 plane.
Edit 3/20/17: This was originally modeled after a #5 Bailey, but I added some of the features of an older Bailey #4 to make it more universal. I also have a #4 Stanley Bailey that this should also work for.
Edit 3/22/17: I also have a #4 Stanley plane that had a much taller knob on the front (also broken) so I modeled that one as well.