Re: merc blueband 150
my merc 150hp is a 1975 as well but serial is 4124419......BTW, it sat for 5 years in the rain never being started and she has just came alive and runs great.....I'd say these ignitions are great and reliable, as well as everything else on them.......Can't beat the old stuff in my opinion.....I'd like to get a hold of new emblems/stickers for my motor after I refinish it's apperance.