G.W.R. Locomotives in the Making

Considered the rarest and most highly-prized of the Chad Valley GWR Series, this fascinating depiction of the construction of locomotives at the Swindon Works was painted by Murray Secretan.
Understood to have been produced from 1936-1939, this puzzle has only been found in the green Book-shelf style box shown, but was made in both 150 and 200 piece puzzles.
See the L.P. Co. London puzzle L.M.S. King's Own for another example of this artist's work.

Artist: Secretan, Murray
Date: 1936-1939
Brand: Chad Valley
Material: Plywood
Nationality: British-England
Pieces: 200
Series: GWR-Great Western Railway
Size: 15 1/2" x 12"
Theme: Promotional
Title: G.W.R. Locomotives in the Making