I'm not sure if it will help but I have a full Mercury workshop manual for this engine it also covers all others mercury 2 strokes from 1970 I think. I bought it when I had a 1988 115 merc 2 stroke for fault finding and it came with a manual for each 2 stroke model merc made. I can zip it up and email it across if it helps with servicing and checking part numbers.
Send me a pm with your email if you would like it sent across.
Mike