Well, silly me, it turns out I had not one, but two MT-60 cranks in my possession, and the crank on the Raleigh that I bought at Goodwill is a Deore LX. That's okay, because one of the MT-60 cranks I had was missing the granny spacers and long bolts, and the other was a crank that my buddy toured South America with, so the rings are all worn out and there is a pedal which is pretty well fused onto it. I also had a very funky Sugino crank that I had scavenged from my friend's backyard along with his abandoned tour bike, which could have donated rings in a pinch. In the end, I used my bare MT-60 crank, some SG-X outer and middle rings, the granny from the Deore LX, and the spacers from South America tour crank. A real Medley; fingers crossed! Also, a good learning experience figuring out which spacers go where and why.
But the donor Raleigh is still coming in handy. It had a Kalloy seat post quick release with the correct bolt diameter, so I can replace the funky, little Suntour that came on the bike. And boy, that Kalloy quick release feels like a brick in your hand, so it'll probably be replaced with a binder bolt at some point.
How do you end up with so many junky cranks? By hauling crap like this out of your buddy's yard:
