The really early Supas (housed in a similar angular 'Olivetti' enclosure to DBBlues' score, but with knobs positioned closer together) as well as some of the earliest 'wide-spaced knobs' Supas were built with both the typical MKII circuit, which Sola Sound was also using in Rotosounds and Fuzzbugs at the time, as well as the 'modified MKI w/ tone control' circuit. It appears that, by the time that DBBlues' pedal was built, Sola Sound had discontinued the Supa MKI circuit, and the SupaFuzz would only ever feature whatever version of the MKII circuit Sola Sound was producing at the time (be that with OC75s, S3-1T or OC81D transistors), until Marshall took over production, c.1968, when it was built with Marshall's version of the MKII.
It looks like the 1966 Sola-built Supa MKI and MKII circuits may have been built in parallel for a while, but - based off secret info & nerdy parts/details analysis - I have a suspicion that the Supa MKI circuit may predate the MKII. Or, at least, that some of the known surviving Supa MKI's might predate the earliest known surviving MKII's. There have been quite a few revelations/discoveries since the data dumps from a decade ago, but in the future we might be drawing totally different conclusions, as long as unusual vintage pedals continue to resurface :)