Well holy shit, thank you for saving me a lot of timeSorry think you right they are not the same :
But I see on a GL650 that for the final drive they use MC7 parts and those are from a CX500 Turbo. So CX650T rear rim would not fit your GL650 but a CX500 Turbo would
I guess if I were him, I would look into a 650 Eurosport swingarm and rear wheel, that would fit his project. however the rims would be silver, If he wanted them gold, he would have to address the color issue.The actual RIMS are the same. you can swap out innards, including spacers and such for a CX500T or a CX650T. The Hub (and hence the swingarm also) is also different. The CX500T has 3 bolts, and the CX650T has 4 bolts.
A GL650 also has a 4 bolt Swingarm and the inards and spacers are the same used as on the CX650T, I know this as I researched and was going to put gold CX500T rims on a CX650T project as I was having difficulty finding silver CX650T rims for my project. I was going to purchase a donar GL650 rear and take the spacers and put them in the CX500T rim.
Anyhow, one other difference is the GL650 uses a rear drum brake while the CX turbos have a rear disk brake. If he is going to make this work, he will have to address that issue as well.