Well this is weird. I set the DVD player to NTSC, thinking that would be the most logical. When I set it to PAL, it started rolling like crazy which I expected. But when I adjusted the vertical hold to fix it, I noticed there was no more picture shaking! Now it's as solid as a rock!

I'm very grateful for all your replies, I'll keep you posted on the plating.
I was originally quoted twice that amount by another company, who, as it turns out, don't plate hollow objects or aluminium. (Wish they'd told me that after I sent numerous pictures to them!)
I'm so happy to have two Predictas working, I'm probably the only one on Australia who does! Can we make it three??
On a different note, is the Sylvania Duelette a hard TV to come by? I'd love to add one of these to the collection.
Cheers and thanks again,
Adam