This bloody forum is turning into some pathetic "Dr Phil/Oprah" helpline for English suffering midlife crisis.
Answer to your question: NO - don't be a git. Its not our fault you denied yourself earlier in life and suddenly regret chasing other 'dreams' that obviously meaned more to you at the time. Ask yourself why you want to do this. If the answer is the familiar "I just love flying and I always wanted to do it" then the answer is still NO. Pretty soon you will not love flying and not want to do it. If the answer is "I want to make a living flying" then the answer is still NO. You are 41, you will be 42 coming back from the USA, then you will be competing with the 20yr old for the same job. You might end up with some worthless instructor rating position earning no money by the time you are 45, doing that for an undetermined time to build hours for a 'real' job. Note: impression from downunder - there are no REAL jobs in the UK. Be prepared to move.
The northsea operators will not want an old copilot.
You will not want to live in a bush camp when you are 45.
You cannot live on spagetti, 2 min noodles or Kraft dinner like a 20yr old (good call Bert...)
You will end up possibly taking a job from someone who is looking for a career, not a reason to feel like they are living for once in their life.
Dr Phil, Steve and Oprah say - chase your dream of sailing around the world or climbing Everest.