True enough, don't remember which disk he bolted up, or caliper bracket used, but caliper of 1500 & 1200 are interchangeable, if not the same #. Never compared # to see. Was sure of swing arm fitting with similar transplant to front end, but 1500 wheel adaptation into the mix has me wondering, not much work to make it fit,& is supposed to eliminate a slight offset in 1200 wheel alignment from factory. Found it weird to read about such a thing,as a slight offset, from factory,if true never bothered me. My question will 1200 shocks fit on a 1500? Rebuilt a spare pair of stock 1200 shocks with about 30 thousand on em, with progressive springs & seal kit for my newest 84 standard. Great inexpensive way to UPGRADE your ride quality, im sure dampers would help even more but cash seems always in short supply. Noticed when cleaning up & putting shocks off bike with other used parts, noticed that distance between eyes is same as 1500's air shock is. If interchangeable, one could redo the spare pair with springs & dampers as well & have a pair in reserve to bolt up to either,redo those when taken off & always have spare for any of your 12 or 15's on hand to bolt up when needed.