King George V. 150 piece

Outline-cut around the top of the locomotive and tender, this 150 piece interlocking plywood jigsaw puzzle was produced from c1927-1936, and appears in various box-types which can be used to more accurately calculate the date.
This is the rather more common version, with a much scarcer 300 piece version also available.
Also shown is an alternative box-type.

Artist: Photographic-Uncredited
Date: c1927-1936
Brand: Chad Valley
Material: Plywood
Nationality: British-England
Pieces: 150
Series: GWR-Great Western Railway
Size: 22" x 8 1/2 (max)"
Theme: Promotional
Title: King George V. 150 piece