I've decided what parts I need for my planned double-fronted Steck house and looking on PlaymoDB I see that there are two numbers for each of the wall with two windows and the wall with a door and a window, and all available from DS for Steck houses at the prices shown:
30 07 9550 Tudor wall with two windows         £1.80
30 07 6790 Tudor wall with door and window  £1.30
30 02 8870 Tudor wall with two windows         £1.05
30 02 8970 Tudor wall with door and window   £0.90
Can anyone explain why there are two versions of each part, both apparently the same but at a different price?  And can anyone confirm that you get the framework and the wall as a single unit?  Long ago I'm sure that the wall insert and the frame were ordered separately.  Certainly from somewhere I've ended up with some frames with no wall insert.