I found and ordered from a place that will cut the gasket to order (at least
the outside dimensions).  
$28 plus $12 shipping.  Here is the link to the product page. 
http://www.equalseal.com/Neoprene-s/1966.htm  
You have to email them with your custom order specs and they will send you a
link you can order that specific item from.  This was a bit more expensive
than ordering twice what I needed and cutting it myself. But figuring in the
labor savings a better deal, I think.  If all you need is 6" then McMaster
is a little cheaper.

I still think it's interesting and a little strange that my flange dimension
would be so much wider than Mike's.  That's a big fiberglass tooling change.  



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Talbot Pratt
S/V  "Remains Nameless"
Red bank, NJ  978 801 1602
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