Peter,
These are extremely well done. I especially like the lighting. Low key paintings are a preference of mine. There is such a wonderful balance in yours. I am surprised though that you use TW. I find this to be rather chalky and avoid its use nearly altogether. Your palette is somewhat similar to mine, though I include a light red ochre and rose madder.
I would be interested in knowing the dimensions of these as well as the medium vehicles you use throughout your paintings (if any).
If you are interested in Vermeer you might find the following web site enjoyable reading.
http://essentialvermeer.20m.com/ It is well presented with some very good information.
I also found this some time ago on the web. It is somewhat interesting.
http://parallel.park.org/Netherlands...brandt/manner/
Best regards