Aerowarriors has Lem Blankenship in a Superbird in 1970 and 1971 and UltimateRacingHistory site has Lem Blankenship driving for Ramo Stott in the #77 Superbird in 1970 and 1971 so it's safe to say it's pre-1972.
The "BLATZ" sign has me guessing it's Milwaukee.
