With leaving the EU most of the attention seems to be concentated on stuff being shipped from Europe - the US is still a gamble, but a safer one (at present) in my view.A corn cob is on my list actually. As for Blue Room Briars, I am not sure how easy it will be to ship pipes to the UK (I don't know if Her Majesty's Government will want ransom money for it).
Blue Room Briars have been exceptional when I've ordered from them. But if you're worried about it it might be better to look closer to home. Makers like Northern Briars are nearly in budget...
My initial thought was Radice for what it's worth.