Well holy Donkey Kong - it works! That was really quite a nerve wracking experience, putting the connectors back together. Yeah, I know it's old, but - so fragile? Well phew anyway.
Thanks a whole stack for your help there Dragonstomper - really appreciate it.
So I'm not sure what fixed it exactly - but I cleaned the contacts (95% alcohol), pressed down on the chips a little (one of which clicked), and that was it really. Now to reassemble the thing properly. More nerve wracking coming up.
I can't tell you much about that RAM board - it would have been done back when I was more interested in playing with Star Wars toys and reading comics, and getting to school on time. But I'll bet it wasn't cheap for sure.
The picture is snowy as expected - but pretty badly so. Was it always that bad?
Donkey Kong lives on. Now I'm thinking AV mod .. the picture is dreadful!