The name Powertone was used only on snare drums until 1970.
Starting in 1970-1 Powertone was used to describe kit drums as well as snares, and the Holiday name went away. The Powertone name was used until the 9/72 tags came in.
For a period of time there were Power Tone tags with the name in 2 words: the drums are the same, and I've never been sure whether it was a conscious decision to do so, or merely an anomaly that occurred when a supply of tags was ordered. There are also a series of tags with no border, some with a different color ink, etc. All of this occurred during only a 2 year period - and there were no changes to the drums.
The Fullerton era was 1969 until the end of the company in 1983. All of these name changes happened during the Fullerton era.
By the way, in the literature itself, the 'Powertone' model name was only used up until the 1970 catalog. The 1973 and 1976 catalog had no reference to the name except the page for the parade drums, which were available in Dynasonic and Powertone models.
But: the price sheets still referred to the basses and toms by the Powertone model name until 1978-9 when the XP8's came along.
