I doubt it.
This was really back in late 60s so that was the "first wave"/original ska era. Not the "second wave" revival of the Two Tone etc in the late 70s. . The "thrid wave" was in the 80s.
Little Millie (Millie Small) - shown in that Aywon advert, toured in 1965 in Australia and NZ on the back of her No 1 hit "My Boy Lollypop". That was the first mainstream hit with ska.
I've not heard of any explicit ska connection from the early days of Sharpies.
An interesting, but unconnected item of interest. One of the early ska bands in Jamaica was from Australia /Melbourne. The Caribs went to Jamaica in 1958 and in 1959 became a studio ska band doing many backings for system/dancehall recording in Jamaica. One of the engineers on these early recording was also from Melbourne - Graeme Goodall - for Coxone Dodd and Studio One. The Caribs also worked for Chris Blackwell and Prince Buster in early pre ska days.
The Caribs are re-forming for the Celebration of Melbourne Ska festival. I'm not sure how many of the originals are coming. One of the originals lives in Melbourne.
Well that was summed up very sharply! Glen A Baker got nothing on you.