Thank you Jool for the link to the website, that certainly narrows down the years for those photos by Higginson. It has also given me an idea - check my newspaper sources for possible adverts for the photographers which will also narrow down the years.
Sorry Seoras, I don't have copies of the backs of the photographs but will ask the person from whom I got the images if he can obtain that information and will post that if he is able to obtain it from his source, who I think has the originals.
We have no Doctors on that branch, they were all tea merchants but could well afford an ornate desk, however I'm inclined to think the photographer provided staging to suit the individual, as they were apt to do, so the desk could simply represent a business man. I'm thinking the references to The Dr and Queen Lita were pet names within the family, definitely no royalty on that line !!
Thank you for your help.