Yamaha GT 2000 with 40 pound copper platter.

Almost correct. I feel that they named the series incorrectly. They called them Gigantic and Tremendous. The series should have been named The Satisfier. That is more apt.

And I keep reversing the alphanumeric designation.  Toyota made a sports car in the 60s that they called the "2000GT". It's now very valuable to collectors. The Yamaha tt is "GT2000" or GT2000X.  Sorry for any confusion.

Any idea where to buy this copper platter ? The original can cost more than 2000x 😮

The only person who would need to buy the copper platter would be a GT 2000 owner. Mark.B is the AudioKarma member who arranges for the copper platter. He regularly posts on the GT 2000 Social Group thread over there.