Hi! I recently bought a 1972 100hp johnson outboard(for $25 bucks) that needs a power pack. I believe the one on it now is an aftermarket one, it says ronken on it and the number is 50A78105K01, it also has IMF 500 DC, and 8442. The model number on the motor is 100ESL72R, and the serial number is J3699383. Does anyone know what the replacement numbers of the power packs that will fit this motor are? Also I have found some that supposedly fit this motor but they look completely different, and without the numbers I don't know if they will fit. Would the fact that they look different matter? Thanks in advance!