I bet they Will find Bridgestones that fit (probably 2 of their current front tires)...
The 67 (titled in 68) GTR I'm working on, that I've owned since '74, has 27K miles on it. 13K when I took possession and 14K since. I thought that was high mileage...
Current state of my engine is needing cylinder repair and a crank rebuild. I last rebuilt the crank when I acquired the bike (it was done by Rockford...:-). The degree of the upcoming crank rebuild is TBD as everything is free turning. Need some expertise beyond mine applied.
Likely your 40K motor has been gone through at some point. I know they are reputed to last forever, but my experience is that cylinders tend to score at something less than 15K (even with diligent oiling system maintenance).
My cylinders should be back from Millennium pretty soon, so going to try their Nicasil plating this time.
Good luck with your new project!
...bert