Constabulary

if you have such information why not sharing it in the public forum?

okay got you - so I think a Singer 78 / CONSEW 28 could be a choice. They have no feed dog and a slotted needle plate + needle feed but it is not jump foot machine. Feet work as on triple feed machines. So just a suggestion. But parts & feet are rather hard to find.

wondering why you are focused on a jump foot. Why not triple feed like the Singer 111W156 / 111G156, Juki 563 or similar as Pfaff 145 / 545 Adler 67, 167, 267 and so forth...

could be a bent needle, bent needle bar or a worn out needle hole in the needle bar - just guessing. I would try replacing the needle bar .

this: https://www.college-sewing.co.uk/accessories/chair-stands-table-tops/machine-support-rest-pegs.html

150 is a steal. I´d buy it in a heartbeat.

The FERDCO seems to be a SEIKO STH-8 of some kind - seems it has a heavier hand wheel. https://www.seiko-sewing.co.jp/en/products/sth-8bld-3/ I know nothing about Union Special machines but it looks like a high speed tailor machine

I guess it is ALEXA compatible too. Alexa: sew me gun belt... no... guitar strap... no... ahm... sew both and make me a coffee... no... chai latte Answer: Yes, I will sew a strap on your Chai Latte and make a coffee colored gun belt for your guitar.

wondering if there is a hand cranked version of it

as far as I know the singer attachment screws fit: https://www.ebay.com/itm/143367841409

main question from my point is what do you want to do with the machine? Just darning I guess cause the machine has no feed system to feed the material for achieving a constant and equal stitch length.

I´ll check my records but I don´t think I have a parts list. Your pictures are fairly small Its hard to tell what is going on... BTW I once uploaded a few more files here, some are for a similar Adler machine but the basics are the same. https://leatherworker.net/forum/topic/113978-old-pfaff/?tab=comments#comment-737306

Increasing the foot lift and decreasing the foot pressure can help to gain a little bit stitch length. Other than that it most likely is the bell crank lever tip that is worn down. You can buy made in China Bell Crank levers new but you often have to modify them to make them work for the ancient 29K models. Some years ago I did that on a 29K1 and it worked. Or you rebuild the bell crank lever tip by brazing or welding and file it into shape again. The tip diameter is ~5mm on a new bell crank lever. But keep in mind other parts on your machine may be worn too so it could be more than just the bell crank lever. This was my restoration 10 years ago: https://leatherworker.net/forum/topic/60554-29k1-pre-christmas-barn-find/ And this is the bell crank lever https://www.ebay.com/itm/162385595622?

Please post pictures of your machine and the parts you have problems with. The Singer 17 is a very similar machine if you need a manual look up a Singer 17 Manual. However here is a German language manual for your machine. Not sure if the Singer 17 parts are interchangeable but in case you do not find a spring I would try a complete new Singer 17 or Singer 16 tension unit. Not a big loss if it does not fit: https://www.ebay.com/itm/191942998278 https://www.ebay.com/itm/143871720894 Pfaff_23_Manual_-_German.pdf

328 and 214 are the same - 214 is more the US & Anglo "name" and 328 is more the continental European "name" for the same needle. 214 / 328 have different shaft diameter depending on the needle size. This is quite unique and I do not recall a 2nd needle system having this. I have not seen enough 216 needle though. I run my 132K with 214 / 328 and so I did with the former 133K. Maybe this older thread helps too: