I don't know what year they came out, but I think the RTs & LTs had painted cases, the rest had black with the matte finish.
Here is a write up I found on ebay from Duncan Beemers:
BMW K-Type III Integral Saddlebag
Mount to any K-bike (excluding the K1) from 1984-1997 with integral mounts
K75, K75S, K75C, K75RT
K100, K100RS, K100RT, K100LT
K1100RS, K1100LT
Fits Mono-Twins with Integral mounts
R65, R80, R80RT, R100RS, R100RT, R100R
Type 1 has locks that needed 2 hands: 1 hand to lift tab up and the other to lock it. Has suitcase keys with a number 40-69. Badge and Reflector are simultaneous.
Type 2 has locks that could be matched to ignition key, lock cylinders facing inwards, as well as similar looking lids/covers to type 1.
Type 3 has lid-mounted locks facing outward, as well as scuff pads making it a heavier lid. Badge positioned above reflector.