Just tested the glowplugs. Wasn't too happy with the results, heh.
Started by removing all 4 from the engine...from rear to front, numbers 4 and 3 didn't have that much carbon buildup on them, but #2 and #1 did. I thought "oh there's the problem! #1 and #2 are bum!" Well...not quite. Exactly the opposite, really.
I couldn't get to my battery charger, so I just tested them in the car off the car battery. To verify the relay worked, I took a spare large-thread plug I had laying around for my car and hooked it right up to the wire from the relay. Turn the key ...yay! Glows beautifully. So, relay works (woohoo!). To establish a ground to the plug, I just nestled it in the ground frame on the back of the engine. I then took all 4 and tested them this way. To be sure I had a good ground, I tested each three different times and re-positioned in the frame hole if they didn't glow the first time.
The results....the two caked with carbon are good. The two for the front of the engine...uh oh. Explains a bit of the hard starting, heh.
Also, I took pictures this time!
Now I just have to figure out how to get them on here in a decent enough resolution...so pics to come later. The majority of them are of underneath the car, where the leaking is coming from.