Lu,
That was the Wezzie 1, which had a cartridge initiated avpin starter, the problems were never the cartridges, it was the charge of avpin you carried if you were landing away and had to re-start
.
The Mk 3 had an air starter, much more civilised, and the Mk 5 was an all-electric affair on the 2 gnome donks ( a la Sea King).
Westlands may have copied the idea for the coupling gearbox, but came up with their own design, as the T58s were horizontal and the gnomes at the same angle as the main shaft from the coupling gearbox to the main box
.