I did one up AK (after kids), hunted high and low and found an 87 which had spent most of its life on the road. I stripped it down, regreased everything, replaced some linkage bushes, new chain and sprockets, new piston kit (motor was in good knick), picked the exhaust apart and removed the internal baffling, alloy muffler. rejetted it and it was a great bike for a casual user. it would match a 99 kato 200 in a straight line but the suspenders were a little plush for fast riding (I didn't redo the shocker $$ as it had good damping but clearly needed a service!)
very enjoyable little bus, great in the tight stuff and surprisingly agile on hills. I would hunt for a motor, there is plenty about as the rear linkage, wheels and swingarms used to wear out and were expensive to fix. always check the rear wheel bearing housings in the hubs, it was common for punters to ignore a crook bearing only to find the hub would oval out real quick, plenty were glued up with loctite and shims over time.