Yes, that is a very strange presser foot indeed. And no, I’d never seen anything like it either.
All I can really tell you about it is that it’s one of the two presser feet we found lurking in the base of that machine when we bought it in last month, they’re both hand cut and folded from aluminium sheet, and I have not the faintest idea what they’re in aid of, as folks used to say.
However, knocking one of these up is certainly the sort of exercise I used to get set when training as a precision engineer in my yoof, so my money’s on somebody learning to be a metal-basher of one kind or another.
One thing’s for sure – it’s just taken me nearly 15 minutes to work out precisely what shape you need to cut out of a piece of aluminium sheet before you start bending it into the more complex one of these two, and in what order you do the six folds …