A question for you Gretsch folks. Did the double tom holder used on the Rock 'n Roll setup change a few times during the years that setup was offered?

I see some with clips on the toms to slide them onto. Those seem to have a wood block across the top of the post. Then I see a similar setup but with spades sliding into the typical diamond shaped tom mount and then a third one that had the spade setup, but didn't have the wood block and instead had a projection from the mount to steady the bottom hoop of the toms.

We these all used at the same time or did that mount evolve?