Posted for "Ron Raby" <ronr@advanceddesign.com>:

 Chat
 
 I got the same cooler new and a new vernatherm. The seat damage was in the
cooler. I considered making a tool to cut or grind the seat. I think a tool
could be made to thread into the spot where the vernatherm goes  and possibly
lap the seat with grinding compound similar to the way you would lap an engine
valve.
 
 Regards
 
 Ron Raby