Water leak-lower unit (and thanks 12Footer & Moving Target)

[trumpetbucks]

I have a '72 Evinrude 100HP Starflite that I got with an "as-is" $300 boat. Special thanks to 12Footer and Moving Target for advice that led me to getting it to run (one loose wire on side of engine and some Engine Start spray into the breather intake - it fired up and runs VERY well!). Now I am thinking I should probably replace the water pump / impeller sometime pretty soon - mostly as insurance. My question is this: When I got it running, it looks like there is water leaking around a small section of the lower unit seal. How big of a problem would this be? (I know it's not normal but that part will be under water!) Would this problem be fixed when I replace the water pump on this engine?