A couple years ago I bought a low mileage Seed (black/red/silver) '89 MC18 R5k with some light cosmetic issues. It did come with some new spares--basically reeds, a carb rebuild kit w/jets, and a whole top end except for the barrels and cylinders. I took it off the road to do a fairly comprehensive refurbishment. Here's a list of the mods.

Chinese fairings in the white/blue/red and a spare tank repainted to match (for a change of pace while I hunted down original Seed plastics).
Powdercoated the original MC18 wheels gold, the fork lowers in Ohlins silver, and bought an extra set of white MC21 wheels for the 17' rear (so I can mount Pirelli Supercorsas).
Ohlins fork internals with Tyga billet adjusters. Required cartridge style NC30 uppers to get rid of the archaic damping rod system.
Ohlins HO206 shock.
Ohlins steering damper.
New DID ERV3 520 chain and sprockets.
Tyga billet rearsets, clutch and brake levers, and steering stem nut
I've rebuilt the calipers and installed stainless brake lines and EBC HH brake pads.
I've refinished the top triple, handlebars, clutch perch and various brackets.
I've got a JHA exhaust which I haven't mounted yet. Should I? I had the chambers refinished satin black and I rebuild the cans myself with carbon fiber sleeves and gloss black endcaps.
I've also been accumulating original replacement Seed fairings and lots of spares from Japan, including a crank.

How it arrived:


The reason it took me two+ years:






I also was recently transferred from Chicago to northern Utah for the next year. The riding is spectacular and there is an amazing canyon road practically out my front door.

How it looks now: