I can't tell you what was in someones head when they did this because I don't know of any reason other than maybe the last belt fit loose so they "tried" to make it tighter.I would take a Dremel & grind off the high points of punch mark & called it fixed.
I was working on a machine last Sat. that needed one & found out we are out of them,I will be ordering more soon.It is screw #200082.Here's a parts list for the machine herehttps://www.supsew.com/download/Singer/Singer 111W155.pdf
The stitching looks pretty good.Here's a pic of the collar on the inside of the handwheel it's just alittle under 3/8" & also a pic of the standard old style of hinges for an industrial machine,while the ones you have will work they are for a home machine & the pivot pin is much thinner.
111w flywheel.html
It's odd you have that much shaft sticking out,it's usually flush.There is a collar cast into the other side of the pulley is it on there?Yes the 2-screws are all that holds it to the shaft.
On the backside of the machine there's a wingnut adjustment that has L,M,H loosen the wingnut & move it so the line is on the H & report back what happens.
The circled cam controls the timing of the walking feet,almost all walking feet machines have & many times are not adjusted from the factory correctly.
441 top feed cam.pdf
I always adjusted uph machines so the needle is in the material just before the inside foot comes down & meets the feed dog,this way when the machine gets wear on it the inside foot doesn't end up pushing the material foward as it sews.
No,it's OK,that's a good idea using the lower cost feet like that & if it works for you that's great.Oh & always chime in whenever you want this board is all about everyones different ideas & experiences.That's how we learn from others.
Dana, Yes these feet will work & we can also get these chrome plated steel feet & sell them @ a cheaper price BUT we've found so many leatherworkers often sew moist or wet leather which interacts with the chrome & makes it peel off making the steel rusty.The feet we sell as stated on our website are made of stainless steel which will never rust.
Try sewing on it w/o putting the thread through the needlebar thread guide,if it sews better you need a new guide as they many times get a groove cut in them from the thread.
In all my years of working on machines I've never seen this happen on a shoe patcher of any brand.Sounds like someone might of taken the cam by the handwheel off & re-mounted 180degrees,that is why your having so much trouble timing it.So try knocking the pin out urn it half way around put the pin back in & then re-time it again & it should work.