Norton Commando 850

Can someone please tell me when the Commando 850 was launched.

Sometime in 1973, not sure of the month though ...............
Someone else will know I'll bet.

The Superplus ! Brochure shows the new commando 850 models.

Have a look here if you are interested enough.
http://users.bigpond.net.au/nortonfan/history.htm

Purportedly, the first 850 was built in April of 1973 Serial #300000 (per NOC). Of course, the same source says the last 750 was built in October 1973, but mine has a build tag of November 1973.