There was a post on the SL forum that addressed this problem in the 107's which have a two-stage thermostat. It recommended drilling three holes in the perimeter of the 'stat and helped keep the temperature under 100.

http://www.peachparts.com/shopforum/showthread.php?threadid=84763

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe