Which activators would you use?
The power and signal in the same cable trick should be pretty easy. You could probably even build one from the DS5 schematic so if you ever decide to use a Series bass, it would be compatible.
I'm still figuring out where to put my 5 pin jack on my Starfire. I'm leaning to doing it on the side instead of the front.
On another note, I do have another '67 Starfire II (sunburst) that I will probably be putting up for sale. It's all original, but has had a previous headstock catastrophe, which is ugly but stable. OTOH, the fingerboard is one of the most beautifully figured pieces of rosewood I've ever seen. I'll have to get some photos together.