Thanks so much for all this guys, really giving me hope I can fix this.
I actually contacted many immigration lawyers yesterday in UK before my initial post and two were kind enough to give me a free ten minute consultation today. They mirrored what you have been saying in that I have two options:-
A) Don't fly next week, cancel the green card on a I-407 then when confirmation received of that then re-apply with a new spouse visa staring the whole awful process and am advised its taking up to 2 years at present?
B) Get on the flight to JFK and see what happens, Don't say anything to officer about any of this this unless asked. Take proof of intent to remain such as our US tax returns, proof of the new house purchase, proof of rental property in USA, SSN, interviews arranged for work/courses, tell them fact I have no clothes in suitcase as have all life there, marriage certificate (US citizen spouse will be with me), return flight showing over 6 months later, proof of US funds and UK funds, proof of what I've been doing in UK to liquidate assets (building control completion notices for my UK houses) Anything else you suggest? I have an old US driving licence which expired in 2012?
They then saying worst can happen, is I'm not allowed in but DONT get a refusal on my record, in that case just tell them I want to withdraw my application to enter, turn around and go get a flight home - reverting unfortunately to option "A" above 😞 One said if I get an NTA that could take years to get a Judge decision and I would effectively be stranded in USA until this happens? They say however a refusal or completing a I-407 doesn't have any detrimental effect on a future application?
Same one also said I may not be allowed to board in UK by Airline check in Staff - Any advice if that happens? Ask for Supervisor? I've printed off the guidance issued to Airlines by USCIS (thanks Mike E).
One thing I don't understand amongst all the advice you kindly have given is to NOT sign I-407 if totally refused entry - I get it from the point that I would be lying If I declare " I have no intention of permanently residing in the US" or declare that I "already abandoned my prior LPR status by leaving the United States intending to make my permanent home abroad" neither of these are true as I fully wish to continue my residency and make USA my permanent home there and if refused entry I would be applying again asap. But if I complete the 407 at the border it seems its done with immediately, there and then instead of having to sent it to the US upon return to start "A" and then wait for confirmation of it before either visiting on an ESTA or completing another 1-130 which I'm told I can return on an ESTA while that is processed? Am I correct?
Can I ask for a Supervisor at border if entry is refused?
Would you make conversation with Border Staff or simply "say hello how are you?" and present the green card (and UK passport?)
I don't know if there are Automatic booths at JFK but if get the chance would I be better trying to enter on these rather than seeing a person?
I will 100% let you know how I get on, which Ive seen is seldom done on here. Im so so worried that it seems to be down to who I get that day at the border and so annoyed that we made such a mess of this!
Thanks so much yet again
Paul