Didn't manage (didn't dare) to upload this before going-home time on Friday. There is now another string to the bow of the nascent REST alpharama here. You can query the people in the database of 19th Century photographic London (pardon the contraction) at the PhotoLondon website we launched recently. Right now, it only sends you back a list of people matching your criteria (100 records per page) with no details. I will soon produce a detailed machine-friendly record page for each person (an example of a human-friendly one is here)
The querystring takes most of parameters you can see on the form including surname, forename, search text (but not multiple words like the form), gender, year of birth/death, "alive in..." year, place of origin, photographic occupation, non-photographic occupation, and presence of attached images. Here's an example search so you can see what you'll get back right now. Here's a wider one.
There are bugs, no doubt, and it will be of more use when I can send you the person's details, as well as a list of countries and occupations to build queries from. I realise I also need to write some proper documentation. Still, it's a start. Please tell me if it might be useful to you, and what you'd like to see it doing/do with it.