The current implied/oral licence permits him promo use only, it seems likely.

Why not seek to formalise an agreement assigning all rights back to you subject to an irrevocable free licence in his favour to use the recordings only in advertisements for his business - with no physical or virtual sale or distribution rights for him? Or he could put one track of yours on any samplers he put out - one per sampler. It'd be sort of backwards, in that usually you'd want to release the album as such first before any tracks went to sampler or advertising use, but it's a bit like the way David DUndas's "Blue Jeans on" was broken: it was commissioned and recorded for Levis and so many enquiries followed that it got a single release and the rest is history.

Don't waste the recordings - at the very least make sure you have good quality copies and then in a century or two your heirs can release them, or if the UK law changes to permit a private use exemption your family and friends can have copies.

Or how about he gets a distribution licence but you have exclusive rights to sell at your own gigs (a bit like the BCAB Guide Cats arrangement where BCAB are sort of limited to a variant of "charity use".

There must be a way to skin the cat if you confront him and tell him that you can block the project entirely unless there is something in it for you...