Henry Carnell Palmer was my Great Grandfather too. One of his sons, George, born at Castle Eden in 1888, was my Grandfather. George migrated to Adelaide, Australia after WW1 with his wife and young family. No old photos survive that I am aware of.
While I can't help with any of your requests for photos, anything you could provide me with info on the family history of Henry Carnell would be brilliant! Perhaps I could even get some photos from you?
Nearly all the info I have on Henry Carnell Palmer and his children came from another relative in Australia.