I bought this set on ebay recently - it's a set of bricks made of artificial stone, called Buildec, by Lott's Bricks of Watford, in Hertfordshire. They are quite heavy, and feel very smooth and cool.
They come in a box which also contains four bottles of paint.
I think there should have been two layers of bricks in the box. These are the models you can make with box 1:
I have enough bricks to make the cottage, with a few left over for a path and a fence:
I had just enough to make the aeroplane hangar:
and the seaside shelter:
but only by turning some of the patterned bricks so that the plain side faced out.
Originally, the bricks would have been plain, without colour, and then the children who played with them would have painted them, following the directions in the instruction booklet:
The box lid states that no previous knowledge or skill is necessary, and the booklet even gives instructions for mixing the colours (blue, red, yellow and white) to create green, orange, a black substitute, brown, mauve and grey.
It looks like you could order extra bricks, which would be very useful if you wanted to make more than one building at a time, or if any broke!
The little figures by the cottage are 3.5cm tall or less, making this set 1/48th scale, or O scale in model railway terms.
I don't know anything about these china figures, except that they were "an attic find" in Kent, but they have no maker's mark on them. (Sorry, these photos have too much flash - I'll try to get better ones.)
Lott's Bricks were made in Watford (in Hertfordshire, England), from about 1917 to 1967. I found a wonderful website which shows many sets of Lott's Bricks, and says that these Buildec bricks were introduced in 1936. I'd first thought they might be older, but the 30s explains the models of an aeroplane hangar, an omnibus waiting room and a garage!