My guess is 1953 Johnson QD-14 10 HP. I don’t have a carb on hand to check it but I believe there is a fat o-ring like that in the carb. I know the rest of the kit doesn’t apply to that year (except for maybe a hard fiber gasket and a couple packing), but in the parts manual it shows #72 – part #302832 that fits in a recess under a retainer. When I searched 302832 it looks like the same fat o-ring in the carb kit. Maybe someone who’s got a QD-14 carb could verify that.
https://www.aomci.org/forums/topic/rubber-doughnut/
