I have recently noticed that my local B&Q DIY stores are now stocking a very good range of pine stripwood in small sizes. Quite a few profiles are available and the smaller sizes are very suitable for framing etc. in medium sized models and for a variety of other modelling applications.
Even better is that as well as very long lengths, most of the stock is also available in 36 inch (not 1m!) lengths as well which can be very handy if ypou don’t need much. I have just used some to frame up a carrying case for the review kit in the Model Boats Construction Special. I don’t recommend their 3mm ply though. The facing veneer is OK but the backing one is very coarse and splits easily and the sheets are prone to distortion.
Certainly worth checking out the stripwood though.
Colin