The pedals in this wonky old photo look very similar too, except that the placement of the lettering on those is closer to how the two known surviving gold Rotosound pedals that followed (in mid/late 1966?) are printed.
Specimen #1:
Wish I'd been quicker 5 years ago when this unit first surfaced, but it all sort of worked out anyway. I've only seen this particular type of 'MK1.5' board in one other pedal so far - Humphrey Barclay's "Professional MKII", with the 'MK1.5' circuit - which is a similarly unusual pedal, so I can't positively say where the Rotosound pedal fits in the timeline.
Specimen #2:
This pedal was supposedly bought from either Walton's or Pigott's shops, in Dublin, in 1966. Features a very typical 'MK1.5' board, so it's difficult to place in the timeline exactly, but it's interesting to note that the mixture of insulation on the transistor leads is the same as in Pigdog-Steve's Tone Bender 'MK1.5' (which has rather strong anecdotal evidence of having been purchased in February 1966). Many thanks to theemadcap1 for alerting me to the existence of this pedal
Bonus pr0n:
