There is no legal tussle. The law has declared the find treasure trove. That means that the museums that want it have a given amount of time to come up with the money that the treasure value that was declared by the coroners. If they can they get the find and the money is divided between the finders and the land owner. If they can't come up with the money than the treasure goes back to the finders and landowner.
Conder101 that's the way that it should be. But in England doesn't the crown get a cut of the find also? I think that there is some sort of old tradition that all finds are somehow belonging to the crown or have I been nipping to much?
No the crown does not. and apparently they have usually one year to raise the money to satisfy the valuation committee's fair market value. They had a problem like this several years back with a gold penny. Lots of museums wanted it but they couldn't come up with the 400K pounds valuation and the coin went back to the finder. It then sold at auction for 857K pounds. The US buyer then had a problem because the British did not want this treasure to leave the country and would not issue an export license for it. The buyer threatened legal action and eventually the government wound up buying it for in excess of 900K pounds. (The buyer came down from 1,2 million.)
