Have the damp proofing and new timber floors been correctly carried out?

No timber should be directly touching any brick work it should be wrapped in a DPM when it needs to be and cut short of the brick work with the floor boards

Timber must not be in direct contact with masonry.

This is a bit complicated. A surveyor is employed to survey on behalf of the buyer and/or lender, according to the remit. This might be overall property value, might be damp, might be bats in the loft, might be anything. I do not think the surveyor missed the damp, I think the instructions were to value the building. No surveyor can possibly miss the damp. All floor joists have to locate into masonry. It is simple to make these joists impermeable to damp. I can very easily identify with your concerns. But you have bought a Victorian house, so nothing is simple. You will always have various damp issues. If you cannot live with this, buy a modern house. I hope this helps a bit. But, I understand, a complex problem. You need a sophisticated expert, you will be given unlimited crap, I know.

I think some sort of vapour barrier was needed between joists and walls.