Be advised that buying from Holts is very expensive.
Let's say you buy a gun case for 300 GBP.
The hammer premium is 20% more
The VAT you must pay (even if American) is 22.5% of the hammer premium.
The freight is high, say $75 for the example above.
Customs is 3%.
You have a freight service charge of $10 on this end.
Your credit card will charge you a 3% foreign transaction fee on all of this.
Many CC firms give you a fake exchange rate that earns them an additional 3.75% vig!
So that 300 GBP gun case is now a $600 USD gun case, maybe more.