If there is a desired float level spec. I don’t know of it. There should be a notch on the lower part of the float pin (needle) where a clip goes. This positions the float on the float float pin. Another clip goes on the top of the float to hold it in position. If your top clip is the friction type they work pretty well. The ones with a screw can be troublesome. Recently, having an issue away from home, I wrapped some wire around a smaller dia. allen (hex) wrench and slid it over the float pin. This worked well and is staying. As the cork is a natural product, its density can vary so two cork floats of the same dimension may produce a different fuel level in the bowl. Also trying to get an accurate measurement with the float bowl cover off could be a challenge. You’re more likely to have an issue with the float pin not seating, causing the carb. to run over. This is the result of corrosion, mostly in the seat. Putting some toothpaste on the needle, and spinning it in the seat, being careful to keep the needle straight up in the float bowl, can help achieve a better seal. Some pictures attached as to how I test how successful my attempts have been when a motor has this style of float system. If I can keep the carb from running over for 5 minutes, that good enough to put the carb on the motor, remembering to shut the petcock after running the motor. Its been my experience that the best seal is achieved from the vibration of the motor after running them for an extend period. At some point I’ll forget to shut the fuel off and that’s when I find out if a good seal has been achieved, however the fuel shut off is easily accessible on these early motors for a reason.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.