The original was a perspex, plasticard, brass,
aluminium and wood beastie measuring 24 inches long,
give or take a smidgen of an inch.
Anyway, after much wailing and gnashing of teeth and
about 3 months I was about to assemble the thing when I discovered that
people dropping in for a visit unannounced can have awkward consequences.

Too late, they spotted it and the pleading and mumbled 'want one' started.