Singer 211G166 presser feet

[Silky]

I have recently acquired nice Singer 211G166 that came with several sets of feet. Various size cording and a standard flat set.

The # on the flat outer foot is 517538 Made in W. Germany which is the same as in the parts manual. But, when I look online at the various stores, all of the feet listed for this models part #'s start with 240***. This foot in particular seems to be listed as 240148, .

The main thing I see is that the 517538 that I have is somewhat shorter from the bottom face to the mounting hole than the cording sets buy about 3/32". The cord sets hold the fabric well but the flat foot doesn't come all the way to the throat plate. Two layers of fairly heavy fabric will slide freely when all the way down. I see where to adjust the foot height but am wanting to be sure I am using the proper parts.

Maybe the presser height was adjusted up at some time to accommodate thicker materials, never needing to go clear to the plate for the thinner stuff ? ? ?

Thanks