those are standard Mono shock forks, if you have a non drilled disc, thats from a R65, drilled dual disc set ups are on R80 , R80RT,  R100RS and R100RT . 1985 to 1995,  specific BREMBO calipers are used. they must be the 85 to 95 type.   don't assume numbers you see on parts are actually the part numbers, many times they are just CASTING numbers.  

@2659 Thank you.  If I understand correctly, I need to look for a caliper off a R65?  Does it matter which year?  Trying to keep the cost down as much as possible.  Would like to put this back on the road for someone to enjoy rather than scrapping a perfectly good frame.

Agreed.

Furthermore, on the hydraulic side.... BMW's plumbing layout was expensive and tended to not be self-bleeding. (That is, by design it needlessly trapped air inside the system.) I'd buy a single, all-flexible hose to run from the M/C on the bars, all the way down to the RH caliper. (As opposed to BMW's standard plumbing to the LH side.) Then use the standard Airhead non-flexing U-tube to jump between the 2 calipers. 

Such a unique flexible brake hose can be ordered from Fragola Performance Systems (click name for link). Also note that 1. all Airhead brake fittings are M10 x 1.0 thread, and 2. that Fragola, JEGS, & Summit all consider the 3/8" banjo the same as 10mm.

Here's my Fragola-plumbed brake hose. My only mistake was taking it to the LH caliper, instead of the simpler RH caliper route.