The way I understand it, any Singer button hole attachment should work, as long as it's not for a slant needle machine.
If I were you, I'd buy the one in the dark green plastic box. They are inexpensive (all are used) and work easily with minimal adjustments. You can get the instruction book at ismacs.org if it doesn't have one. Make sure it comes with the metal templates. I think the one from my mother's machine has 7 or 8 of the little metal "cams".
This has some information on the buttonholers.
http://vintagesewingroom.freshwaterfibers.com/2015/11/which-buttonhole-attachment-fits-my.html