The rear spacing on my is 115 mm, it takes a 4-speed freewheel. 4-speeds are difficult to find but they are available except for the wide-spacing versions. I want to find one for rides that have hills and my current granny gear, 47/22 won't cut it. I'm looking for a 26, 28 or 30 cog for my granny. I can find these in the 5-speed freewheels.
I thought I read somewhere 5-speed Reginas used the same inner body as the 4-speeds. The 5-speed small cog extends past the inner body. Here are some pictures to illustrate.
Can I modify a 5-speed to be a 4-speed? Please don't ask me to change my rear spacing to 120 mm, I won't do it.