Well done mate, I had a similar experience years ago when the starter motor on my Suzuki GS1000S crapped out during a "speed trial" late one night, (I think I nudged the starter button at about 145 Mph......) anyway, the wreckers wanted 200 bucks for another used one, but then one of them offered me another complete GS1000S for 500 bucks for a parts bike, so I bought it "sight unseen".
He delivered the bike that afternoon, and my first thought was "What drain did you drag that POS out of?" the tank was rotted through, the seat was gone, as was the front fender, the pipe, and anything else of interest was either bent or busted. Luckily for me the starter motor worked.
A few months later I stripped out two exhaust bolts on my bike, so I thought about a head swap with the "parts bike". When I removed the cam cover, I discovered a pair of Yoshimura race cams in perfect condition! Woohoo! "Hmmmnnnn", I thought, what lies beneath? I whipped the head off (mild port work, but too many busted fins to be desirable) to find a beautiful set of 1085CC Yoshi hi-comp race pistons! Double Woohoo!
I tried them in my bike and they were pretty cool, (120Mph in third gear at 12000 RPM) but for reasons mostly forgotten, I removed them and sold the pistons, cams and cylinder block on Ebay for 750 US bucks (about 1200 Aussie "Pacific peso's" at the time) which pissed the bike wrecker off when I told him, but I used the money to buy my CB750K3 from him, and guess what? I think there's some "trick" bits lurking inside too, ha ha! Cheers, Terry.