Anyone know of a good Descent Core box game organiser like Broken token do for Imperial Assault?

found https://www.gothsonika.com/

problem is they do a nice one but im in UK and its coming out at $60 for shipping to UK.

Anyone know of a good one made/sold in UK?

I use a fishing tacklebox.

You could try:

http://uk.battlefoam.com/descent/

They might have a UK distributor.

Edit:

Just did a quick retailer search and there appears to be quite a few retailers carrying Battlefoam products.