As usual, pics would help :). If the badge is red, and there is no serial number, I am tempted to say 1981 or 1982, but I have seen red badges later than that (although they had serial numbers). If they have have triangular (Ludwig-like) lugs, they could be anywhere from mid-70's to 1982. Tama went to the staircase lug sometime in 1983. If it has an Omni-Sphere bass drum post with flat TAMA lettering (assuming it is original), then it is 1980 to 1982, or if the letters are on a raised block, then it is 1983-1986. Tama Historian's "Tama Drum Guide" has the exact dates that the red badges were used, but the absence of serial numbers tends to point to pre-1982. Serial numbers was a feature of the Imperialstars, aimed at the tourign musicians and designed to help insurance and deter theft, but at some point in 1982 or so, all grades were serialized.