I found a beautiful little Singer on e-bay last month and it is sewing like a dream. It is a little bigger than a Featherweight, and about 10 pounds heavier. It is a 99 straight stitch machine that came with attachments to do ruffles, attach binding and do hems. It is so cute! Since learning about these 3/4 machines I really wanted one, so kept looking thru e-bay for one that I could pick-up locally. I got lucky and found one, one very well taken care of, for $50.00. To me, the price was well worth it for it's near perfect condition. The 99 will do heavier materials than the Featherweight, it has a stronger motor. The Featherweight is good for the quilting classes because of its compactness and light weight, however a 99 in it's case will also work well due to it's small size.
Older Singer model numbers 99, 28, 128 and 185 are considered 3/4 machines, meaning they are smaller dimensionally then the same full sized machine. Singer 66, the most common of the treadles, is full sized, 99 is 3/4 sized. They are the same machine, only size varies. A 27 and 127 are full sized, the 28 and 128 are the smaller verisons, 27 and 28 are older than 127 and 128.
A Featherweight, which many quilters want and will spend several hundred dollars for, is a 1/2 size machine and weighs 11 pounds outside of the case, 19 pounds in the case. It too, is a straight stitch machine. Older models don't have reverse, newer ones do. Featherweight machines were made between the 1930's and 1950's, and a specially made card table with a cut-out or a cabinet was made for them. The cabinet is very hard to find, the tables sell on e-bay for almost as much as the machines do.
I hope to get lucky someday and find a Featherweight, but don't want to pay the going price for it now. Someday, Someday. Edey