I would also say use a new one.. only reuse.. if you put the thing together and took it apart aging and dident start up.... But yes the thing is there is a "ring" that is "crushed" to seal... it will be best to get a new one..
For that head you might want to run a high compression gasket. Cosmic makes one, I know its used for the CT sonic 240 kit though. And Allen Knowlles from CT has told me over the phone that if you dont have a new gasket and the old one was not used much, just heat it till its very red with a blow torch then let it cool and you should be fine.
i saw that but didnt bid because it didnt say how much was taken off. same with the ones from summit on ebay i asked them how much was milled off and he gives me some sh*t about "enough to make a differance" and woudlnt tell me exactly how much like it was a trade secret or some sh*t