what you do in a case like this is first go on amazon and buy a gold-melting kit, and melt the whole lot into one ounce pieces. then sell a couple at a time at different shops that buy gold, with the story that you were cleaning out the junk left behind by a favorite uncle and you found them in an old coffee can on the back of a shelf of junk in the old guy’s workshop ... if that don’t work in the UK, then fly to the USA and travel around for a few days to make the sales, perhaps enlisting the help of a native friend if necessary ...
That leaves an electronic trail.
First, go to a public library and try to find a paper book on gold smelting, to learn the technique. If you can't find it there, go to a book store and buy the book for cash.
Then try to buy the tools you need, for cash. Preferably piece by piece, in different stores.
That still leave the problem of where to melt the gold, at least for those of us who live in multi-unit buildings, with no private garage or basement.