I just bought this 1982 Yamaha 9000 Series concert tom set. It was in very good condition but needed a lot of cleaning. 6, 8, 10, 12, 14, 15, 16 concert toms, 18' floor and 14x22 bass drum. The model of drums was confirmed for me by Robert at Yamaha Drums USA based on serial numbers and model numbers indicated on the badges.
I disassembled each drum and cleaned the lugs, mounts and tension rods with a water/Dawn dish soap solution in my ultrasonic cleaner (cheapo from Harbor Freight). The device never worked well for me until I used Dawn in the solution. Now it's brilliant!
Since the drums have a cortex-like finish (I don't know what Yamaha calls it), I used Nu Finish car wax to clean and shine them. Nu Finish does a good job, although I had to scrub some of the dirtier bits quite a lot to get them clean. But worth it!
For the rims, I used Flitz polish. There was minimal rust. Not bad for a 40 year old set of drums.
The snare that came with the set is a vintage Tama Granstar 6 1/5 x 14, chrome-wrapped birch wood snare. It is missing one of the original lugs and has a pdp lug in it's place. The hole spacing was off ever-so slightly, so they elongated a hole to make it happen. Coulda been worse.
I originally planned to modify some of the drums to two-headed drums, but I'll wait and see. They are fun to play as is, kind of like achieving my high school dream of owning a Ludwig Octa-Plus set. I don't expect to gig it as is, but maybe if something comes up I can take out a five or six piece.
One problem with the set is the "double tom holders." They have triangular heads on them made of pot metal or aluminum. Each one of the tightening nuts has been pulled through the original metal casing and therefore holds very poorly. I ordered three new ones at about $60 each. Is this pull-through problem common to older Yamaha sets, or was my set owned by The Incredible Hulk?