Just yesterday I was discussing this with two Morgan mechanics, and they said you should worry if it DOESN'T leak. The one-shot is deliberately designed to send engine oil dripping down the kingpin and to your garage floor.
Some owners have disconnected the one-shot and replaced it with a grease fitting. The mechanics said that grease would not be able to make it all the way down the kingpin, and a second grease fitting would be needed further down. They have done this for several racers and would be able $$$$ to do this for me for $$$$$.
I've only had to replace my kinpins and bushings once in 30,000 miles, so I'm not going to complain about the oil spots. Part of the charm and ...
