Suggestions for a basic toolbox

Hi tool kit only as good as person useing it

Mole grips or similar would be my contribution & just bought a Leatherman Wave so will see how useful that proves 

Cable ties, you can't have too many cable ties, and if you don't have one that's long enough you can daisy-chain shorter ones together.

Corkscrew.

Heavy duty Velcro and a tube of 'no nails' glue 👍

Gaffer tape and WD40 . One will fix it if it moves the other will move it if it's fixed.

Do you carry a car tool kit?

As others, gaffer tape - the best you can find, WD40 or similar, velcro strips - heavy duty is probably best. Then unless you have surplus tools at home which doesn't seem likely, I would buy as you need. I would check the van to see what type of screwdrivers/socket set you might require to ensure you can undo or tighten as required. Not only check the 'head' of any fixings, but also how much room you'll have to work on them.

I carry a hammer [only used once and it really needs to go], a varied set of screw drivers of different lengths and heads, socket/spanner set [used most] including those star shaped thingies which can be very small, pliers, and an adjustable spanner which I use when changing the gas tanks. Most of these came in a 'car tool kit set' I bought many years ago.