Wow!! From the quality I see so far this is going to be a very interesting build which I´ll follow closely. Thanks for linking my build, I´m really honored. Nice coincident with the number

(my 990 never got any letter increment, however. Indeed, it never got any letter at all and is now discontinued

)
Your master (half) tire looks very good. Maybe you already know there is
a small company in Germany (sorry, only in German) making flexing tires on request. Like
the tires on the Braeker wheel loader. They also make custom tires from masters like yours. Only problem is they currently have difficulties meeting demand (one key person being ill).
In any case, I wish you great success with your build.
Stefan