For Jim, particularly: Was surprised to see my query from last year so recently viewed. More ironically, I had just been checking on some data about Puch rims this morning, so I can maybe make your life easier.
First, brake plates for 5 star mags and spoked Puch rims are the same 80 mm drum diameter. Grimecas have diferent brake plate (90 mm). Same for the brake pads.
Second, ball bearings: Spoke has 13 x 3/16" per side, rear with 12mm axle and cone and 11 x 7/32" per side front with 11mm axle and cone. THIS REFERS TO PRE-1980 SPOKE RIMS. From 1980-on, spoked rims had 12mm cone for rear and bearing 6001RS. FRONT SPOKED RIMS REMAINED SAME AS EARLIER.
5-star mags: Same bearing 6001RS and 12mm axle for rear. Front had 11 mm cone and 13 x 3/16" bearings each side. These rims came out after 1980.
Grimeca/criss-cross/snowflake rims: Front 11 mm cone and axle, 10 x 1/4" ball bearings per side. Rear 11 mm cone and axle, 11 x 7/32" ball bearings per side.
After all my research. Does that make life easier?