I understand now. What you might try is to run an ad here in the classifieds section. There are members and guests who read those and not here….and vice-versa. Can’t hurt; it’s free
.
.
Also there are a few people on youtube running their 1955 3HP Evinrudes. You could try contacting them to see if any of them still had their engines and whether or not they would be willing to have a look for you.
.
https://www.youtube.com/results?search_query=1955+evinrude+3+hp+outboard
.
.
Your present cowling fits except for the carb control openings? Have you compared your carb to the illustrations and part numbers in your parts manual?.
