Bob Mannix wrote:

If you feel redress is justified, you can take out a small claim against him
in the county court

Thanks. I know about that, but your advice is welcome all the same.
That's the legal avenue, but I'm reluctant to go down that route
because of the delay it will cause, and the hassle in trying to get
the money out of him at the end of it.

What would happen if I got a judgement and he declined to pay?
Ultimately a bailiff could seize goods to the value (at auction, ie
goods to more than the value). I already have goods in my possession
that are worth what I have paid as a deposit. If the alternative is a
lengthy legal process with an uncertain practical outcome, I'm
inclined to keep them, fill and sand them and make use of them. It's
possible that he might take this cutting of his losses as the best
outcome, in any case. FWIW nothing was written down or witnessed,
concerning the order. We'll see.

Regards
Richard