Since the transition period is so close, we know that the SSB #1 and Square Badge #1 could show up within the same kit. Tiburon said the kit came undrilled and without hardware, so the drums were stocked as individual virgin items within the stores inventory. It's possible the tom tom and floor tom sat on the shelf longer than the bass drum. The snare with the Drop G badge is the odd ball. Maybe the snare had just arrived at the store. Once we find out the original date of sale, we might have a better understanding. If the date is in December 1979, it might make more sense that the kit was put together with three different badges. Of course, we need to find out if the Drop G badge was available for drums in the 1980 catalog. If the date is in the beginning of 1979, then I'm stumped.
Maybe KCDrumDad will chime it. He is the VDF member that is working on a Gretsch Dating Guide.
-Tim