Welcome Tex, If you have by now got the case with the two seals off, it won't do no harm to replace them as they can be bought off the shelf from most bearing shops.
A thing to note though (maybe overlooked by our very tallented Mr Spokes
)
only one of the seals (the inner one) is the crankshaft seal.
The outer seal seals the case to the starter gear and if you look carefully you will see a little hole in the case that (daft as it sounds) lets a small amount of oil past the inner crank seal to lubricate the starter gear.
Over time some of this oil WILL find its way into the generator case so what people think is an oil leak is no more than what is supposed to be there.
If it is excesive though, replace them.
Sam.
