From all the info I have I'm thinkin its 1970. Damn thing is older than me and in better shape!
WSM 22 ~ WSM 18 ~ Maverick ET-732 ~ Flaming Fast Thermapen ~ Weber SS Performer ~ Weber 22 OTS ~ Weber 22 OTS ~ Weber 22 OTPlus ~ Weber 22 OTS ~ Weber Q300
When all else fails just ask yourself, WWGALD???