Alright, a post I can respond to as I own one of these for tenor---
I own the bare brass tenor model for a Mark VI---I can't remember the number but its listed as the thin wall model. Using it on my 183,000 Mark VI with A Morgan 9 E or M and Jazz Select 3M filed reeds. Took me a while to get used to it, even the thin wall is darker (to me) but I really like it now...
ving
(After checking on the neck, the taper is marked as the 66H model)