I have wheelpants and brackets that I I just removed. They are off my 1953 180 but appear to be the newer style, not the wheelpants and brackets that were same as the 170s. Shoot me a message and I can send pictures
As I recall, the mounting plates are just flat material (thickness?) cut to a shape, and drilled with nutplates added.
If so, they wouldn't be hard for someone to duplicate, IF they had a good drawing (preferably full size) or a mounting plate to use as a template.
I wouldn't think them nuts would be hard to find.
Spruce sells some "Grove aluminum wheel pant nuts",
you'd have to check that the thread and dimensions are what you need.
I've seen lots of pantie-less Cessna's sporting the wheelpant-style axle nuts.
My old C150/150TD had them, I chucked them into a lathe and turned off the threaded "tit".
You could probably find someone who trade their wheelpant nuts for a set of regular nuts.