Edwin as a Knibbs name suddenly appeared in my line in 1821, and as I said before, it was given as the first or second Christian name for three sons of the same parents. One of the sons went on to have his own son called Edwin William in 1844. I had never come across it before. Given that all these Edwins were living in London, it seems more than a coincidence.
Francis is also a strong name in my line. The father of the three Edwins was Francis. He married a second time and had a further son called Francis Edward who was born in Stepney, London. The first Frank appears in Kensington, London in 1901. He was Frank Robert KNIBBS - I think he would have been my dad's cousin.
I've not come across any Isaac's other than a couple marrying into the family.
Are you able to open GEDCOM files? I am. It might be an idea to swap to see what other comparisons there are?
Now that I have established ties of my line with London, I've subscribed to the London list on RootsWeb. I've searched their archives but nothing at all on Knibbs. I've also put an enquiry out but no response as yet.
I have your e-mail so could send a GEDCOM if you like.