I am currently in the middle of the same exercise. My GGGGrandfather, John Casement b 1791 IOM moved to Liverpool in early 1800's.
But it has been difficult tracing him further back possibily because he was illegimate.
I'm currently taking the approach of tracing various Casement families from earlier years forward.
Namely:- Those living at Kella, Grange, Lonan and Ballacorey (Andreas)
Currently Thomas Casement b abt 1625 (Kella), furthest back; Kella was sold abt mid 1700's (Sir Roger Casement family), to Casements at Grange.
Still haven't found the direct link (Robert?) between Grange and Laxey.
I am directly related to a living Casement (DNA Test proof) who's family was at Ballacorey, Andreas.
But as yet no proof of links between my GGGGFand Ballacorey or links to Grange and Laxey.
If you let me have your email address, I can keep you informed of any developments in this long and slow process.
ROY@ROYCASEMENT.COM
I would be interested in your Laxey family research.