No6 mk1 2-in rocket launcher questions

Gentlemen!

I’m interesting for this RL, but know quite a bit about it. I know that it was predecessor of no7 mk1 RL. It was tested with RN Westland Whirlwind and deployed with Westland Wessex helicopters in early 1960th. When and why was it replaced by no7 mk1RL? How was it mounted onto Whirlwind? Had it differences in the mount to the Wessex weapon platform? Which sight was used for firing from those launchers? Was this RL tested with RAF’s Whirlwinds?

Regars, Andrey