I ended up copying Stielow's design for my "1st gen" Anvil mirrors and turned out great:
https://lateral-g.net/forums/showthr...hlight=stielow

Hey thanks for info, looks like a better option
thanks again!!

b/c I had the mirror/glass that fit already but not the 2nd gen mirror components I ended up getting these mirrors just for the backing and ball joint:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

then I used scrap aluminum to make the bracket and base plate and epoxied the glass and aluminum base plate.