Thickness of TR2-4 SU carb spacer?

["Anthony Rhodes" <spamiam@comcast.net>]

I am trying to fabricate a replacement for my TR7 flex adapter.  As all TR7
owners know these are $40 each and the rubber fails regularly.  I am in the
process of designing a replacement of some sort (minimal machining,
hopefully).

I want to incorporate one of the insulating spacers that the TR2-4 use, and
therefore need to know the thickness of that spacer.  I need to replicate the
0.75 inch overall thickness of the original flex adapter.

-Tony