The Singer 185s are an updat of the 99s. Same internal mechanics, just a newer exterior. They are 3/4 sized machines and do sew quite well.
There is nothing exotic or complex about them.
I got one a couple years ago in trade. As I was cleaning and fixing it up I kept seeing my wife eye balling it. Once I was done, she tested it and declared it .... hers. Oh well.
Joe