[dvd3500]

Thank Jason,
I hadn't thought of the screw-in legs. For my purposes that ought to be sufficient.

I am leaning towards 90 cm so as not to have to lean over to pick up cars ...

The easiest thing for folding would be big hinges.
I forgot to mention the old table had a pulley and cable system to open up the middle and make space for the leaf.

Adding the leaf in might be tricky. By not having the 2 halves slide apart it won't fit as originally designed.
It could simply just be a really small table by itself and I could use velcro to hold it in place...