Why not go with Avons (while you still can)? My car is used exactly as you intend to use yours (i.e. mainly street use with the very occasional track day) and the Avons have been superb. In fact I have another set sitting in the basement ready to be put on in another 200 miles or so. Only...
No idea what date I joined, but I was apparently the 18th member on board. However, computer problems saw a profile change along the way. It's been a great ride, and like James, I appreciate the efforts of Ron and all the other moderators. Still a wonderful resource.
Looks like that has been turned up from the drawing I posted on here back in December 2021. https://www.gt40s.com/threads/looking-for-lucas-608-rear-mirror-parts.55740/#post-570006