update: so I had a question on my reference procedure, so I thought I'd take a minute to go over my process. Thanks to google and other image searches, finding the reference you need is mostly a matter of how good your vocabulary is.
For example for the interior details, I knew the style of house I wanted, but you can't exactly do a search for "cool old stone house with a window". So you have to be tricky. First I tried 'fireplace' and 'hearth' and 'mantleplace' and similar terms because these houses always had these things. I then tried looking at old english pubs, which generally have the same kind of construction, but they were usually filled with people, or too fancy. It's funny, but you just never know what words will get you what you're looking for, so it's a bit of an art to keep coming up with different words that will trigger new images.After more strike outs, I found the magic words: 'slave quarters'. Alot of historical museums have empty rooms set up with period detail, and the construction and details were close enough that I could use alot of what I found.
Once I have all my material, what I find important to do is to put it all together on one sheet so I can see everything at once:
So there's some things in there for detail reference, light reference, palette reference, and human reference. I try to keep everything fairly equal in size otherwise I end up ignoring the smaller images and over emphasizing the big ones. ( in this case I broke that rule because of the importance of getting the interior correct.
So, all in all I'd say it was a couple hours for reference mining and maybe just under a couple days ( including feedback turnaround time ) to complete the image.