There are several posts about the 29k and the 29-4 here on QB. It can sometimes be hard to do searches for what one wants. Trying to find some links for you, it seems like there was something like k29 instead of 29k. A lot of people don't know how to use the hyphen when referring to Singer sewing machines. For example using 29K-4. It should be either 29-4 or 29K4. I know a user named ndnchf did quite a bit of work with a 29, but I'm not sure if here or on another forum. I know there are lots of posts on leatherworker.net about the Singer patcher 29 including
https://leatherworker.net/forum/topi...9-4-questions/ There is
https://projects.foxharp.net/sewing_...eather-patcher that tells of his machine.
There is also
https://ismacs.net/singer_sewing_mac...g-machine.html that has parts lists and manuals for the 29.
I know that cleaning will help a lot, but it is recommended that one do that with sewing machine oil on a cotton ball, or cloth so as not to damage decals.