L.N.E.R. High Pressure Compound Engine No. 10000

One of several interlocking plywood puzzles from Photochrom, which were produced to promote various locomotives in the 1920's-1930's. This colourful reproduction features the so-called Hush-Hush, High Pressure Compound Engine No. 10000 designed by Herbert Nigel Gresley and built at Darlington in 1929. This was evidently Britain's only 4-6-4 loco.
Interestingly, the pattern on the paper covering the box matches that of this Tuck's Jazz puzzle.

Artist: Photographic-Uncredited
Date: c1930's
Brand: Photochrom Co. Ltd.
Material: Plywood
Nationality: British-England
Pieces: 160
Size: 24 1/4" x 11 3/4"
Theme: Railways
Title: L.N.E.R. High Pressure Compound Engine No. 10000