I just thought I’d add a thought to this thread as I have a cousin who was born in West Ealing, which was in Middlesex at the time, it’s now in West London. My cousin’s father was John Beattie, he died several years ago and I think he came from Cavan or perhaps Leitrim which is close by to Cavan.
Don’t know if there is any link to the information already here but I thought I’d throw it in the arena.