I have an original Commando Workshop Manual 1970 models and Onwards that was a 1972 edition and it doesn't cover the 850's so be careful if you purchase one somewhere to get the 1970-1973 version. It is the 3 ring binder type with plasticized covers and was the official Norton Villiers manual. I found it to be concise, orderly and easy to understand, in short priceless.
I purchased a new 750 combat in 1972 and soon realized I'd be spending more than the $1899.99 CND purchase price for parts and service the way the dealer was treating me. I kept asking them to sell me a manual but they were unavailable," besides it would void my warranty if I did my own wrenching on it" I was told. The dealer had his shop split in two. On one side of the show room was a line of Nortons and on the other side was a line of Suzukis. The owner of the shop raced Suzukis and I'll have to say was heavily biases toward them. I began to question why he was a Norton dealer by the way he spoke of them (after I purchased). Finally after getting exasperated asking for a manual I wrote Norton Villiers asking if it were possible to get a manual though them. I received a letter back telling me my dealer would sell me one. The dealer kept telling me you couldn't get them and they didn't even have one. I wrote another letter and I think I got a phone call from Norton Villiers but finally they sent me a letter directing me to go to my dealer because a manual with my name on was being sent to them. The letter also directed me to hand the letter over to the dealer if they told me they didn't have a manual for me. That portion of the letter directed the dealer to phone Norton Villiers immediately while I was there. And yes, it came to that, I handed the letter to my dealer and he took it red faced into his office and made the phone call. He came out and handed me a manual. I wanted to share this story here because I think it was this type of attitude and dealer support that contributed to the demise of Norton Motorcycles.