Just an update on this coin and the 1854/3 that i purchased off eBay from America.
I was charged the 20% on both and as i have numerous times before posted the relevant details and form etc to Border force.
One thing that has changed is previously they have always posted me a cheque ,although today received a letter asking me for my bank details to pay me.
Only takes a few minutes and if your charged to much ,why let them keep it.