Found a couple of links you may have run across:
http://www.videomaker.com/article/17...&gbv=1&ct=clnk
http://www.shopping-advices.com/feat...generator.html
Do you have the "instructional overlay" outlining basic operation? If not, perhaps one of the auction sellers could make you a copy before sending it away. The video technologies article says the manual is only 5 1/2 pages long...
Also, there are two adjustment pots (with hex nuts) tucked up high on the back panel... you may have a go at those... after marking their current position fairly accurately. Best to do once you get video scope going.
And with regard to PAL... they (or you) may have modified the unit's main video board output for NTSC, but the video input you're using might still be PAL... which would probably look squirrely. The fact that it snaps into correctness on occasion leads me to believe it's a sync problem.
Chip