If you scroll on down Calvin's build thread on BritishV8, you will see that those are the wheels he used on his TR250 back in the early '80s. He said they are 15"x7" and very light, but they are 4 of only 12 made. I'm pretty sure he has different wheels on his TR6 now. Maybe you could convince him to part with those?
Dan B.
South Charleston, WV