These can be ordered from "japanparts.com" :) (They speak english)
1205G-083-005 - CG10DE, CG13DE 14-21 days - JP ¥23,100.00 US $197.33
HEAD GASKET FOR COMPETITION /t=0.6
Material: Metal, Silicon Coated, Hole diameter=73.0mm
OR
1205G-083-006 - CG10DE, CG13DE 14-21 days - JP ¥23,100.00...