On 23/08/2019 12:48, Jethro_uk wrote:
Would a crook lock thingie or wheel clamp have made any difference in
these days of battery angle grinders?

I would go for noise.
Buy a cheap (£10) pin alarm, attach to underside of van and the piece of
cord extend it and attach to something on the ground, if they move it
you will have plenty of decibels + as it is attached to the van will
continue to sound as they drive down the street.