Mercury, despite their “Dark Side” reputation, was really good at what you’re asking about, much better than OMC. They had what they called the “Where Used Record.” I have it on microfiche and I am sure, it was printed, at one time.
I searched for this “Where Used” publication. Found two of them, one for $135 and $425. The Mark 30 and all the other related parts that came in the deal will go back into hibernation.
If you want to PM me with an email address I can send you a PDF of the Mercury Where Used Book. It is 314 pages long and too large a file to be posted here. I will use wetransfer.com to send you the file. It is free to use.
I’ve been looking in the “Where used” book to see if my Mark 30 could be retrofitted with a Mark 20 tiller handle and if the parts would allow for throttle control. I matched at least one parts number to both motors. Comparing pictures of the Mark 20 to the Mark 30 looks like the cross shaft might be the same dimensions. If it’s been done before I’d like to keep the option open in case I decide to try the tiller option on another boat.
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