Jewson sell timber, sheet materials and mouldings at Pinewood Studios.
Their mouldings range is similar to that of John Mansfield Timber who continue to supply the studios from their Uxbridge depot. You can find my model of their profiles by searching for "Mansfields mouldings" in the SU warehouse.
This model is provided without warranty as to exact sizes.
Shapes can easily be push/ pulled or follow me'd.
As fas as I know the mullion, frame and cill profiles (bottom right) have been discontinued.