If I leave the Bertha as a Bertha, I think I'll stick with something simple, like the yellow, black, and white design shown in the 1971 catalog.

If it becomes a Ranger, I think I'd go for the 1970 red/white/black design. (Also seen in the 1964 catalog!)

I'm more and more tempted to go the Ranger route. I'm pretty sure I have a bulkhead and coupler to do the job.