I would suggest that you turn your engine to TDC, note the position of your rotor, and yank out the distributor. You have to lubricate both the bushings on the weights, and the upper shaft where it moves in relation to the lower. As often as I have seen the weights seized, I have also seen the springs rusted to the point of imminent failure. You will want to check them as well.
If you want to see the progress on the howitzer, have a look at my thread about it over on the G503.
http://www.g503.com/forums/viewtopic.php?f=27&t=189187