Tiller Handle Replacement Merc 9.8

[Oregon Jon]

Hi there, a friend of mine asked me to take a look at his '72 Merc 9,8 hp since he knew that I liked working on old outboards. I was happy to oblige but the problem is I have only worked on OMC products. His motor needs the entire tiller assembly replaced as the mounting bracket is broken off where it attaches under the powerhead. I would like to save my friend as much money as possible and I certainly don't want to start tearing into an otherwise great looking motor blind. Can someone tell me which service manual would be the best for this procedure and any advice would be helpful.
Thanks.