Interesting topic, especially knowing that some last generation of Aero of Plus 8 (like the speedster) may have the same dimensions than the Plus 6.
On the Plus Six inside the wheel you have a “stamp” with all information.
Standard Plus Six wheels: 8.5 x 18 inch; pcd 5 x 114.3 cm; ofset 26,5 cm
If someone have 2 second hand whelk like the original Plus Six I am interested 😉
Enjoy this sunny weekend !