Brakes

The brakes on the 80 were in pretty sorry shape. The master cylinder was pretty rough inside, not to mention dry from slow leaks around the sun aged 80s plastic reservoir.

Since the front suspension is to be a set of GSXR forks, I took a look at options for brake calipers.
Obviously, GSXR brakes would work, but the Master Cylinder was known to be a bit mushy.
I opted for a set of 06 Yamaha YZF R6 calipers and Master Cylinder.

These came off a bike with about 2k on em.
As a bonus, the R6 brakes should match up with the R6 controls I picked up.
Installation may require some spacers - easily made on my lathe - but it will depend on the wheel/rotors I end up using.

Reference

R6 caliper GSXR swap