Pleased I was able to take delivery of my BJ tandem three weeks ago from John & Ruth. Wonderful machine.
FWIW, we purchased it because Covid has removed our main hobby (dancing) and also we had funds earmarked for foreign holiday which we didn't take due to Covid. So in our case, Covid generated a new tandem.
Very pleased to buy British.
I don't know where you would get a British made tandem with couplers. I asked Steven Shand a few years ago, he wasn't interested.
I think that it is still possible to get a bespoke tandem made by Locks of Sandwich, Roberts & Longstaff, probably others too.
Thorn, Orbit and Circe are all UK based of course and although they bring their fames in from the far east they are still desgined and built to those companies desgins and standards.
Sadly Chas Roberts retired several years ago.
Longstaff don't currently do tandems - I checked earlier this year.
Don't know of Locks of Sandwich.
Had one Thorn, enjoyed it, but sadly 120mm too short on the rear, and made of pretty heavy steel.
Circe - aren't they small wheels and flat bars - not for me thanks.
My BJ is actually branded Orbit as well, and is an Orbit Sapphire Pro, made by BJ. Very pleased to have purchased it.