kit-bashing
n.— «These raw resin ships were then detailed by a process known as kit-bashing—gluing plastic model kit parts to the surface of a model to create intricate areas of detail.» —“The Rebel Y-Wing from Master Replicas” SirStevesGuide.com Feb. 6, 2006. (source: Double-Tongued Dictionary)
Further reading
She sells seashells by the seashore. Who is the she in this tongue twister? Some claim it’s the young Mary Anning, who went on to become a famous 19th-century British paleontologist. Dubious perhaps, but the story of her rise from seaside...
Secret signals on the job: Waitresses at some 19th-century restaurants ensured speedy drink service by communicating with a non-verbal code. One server took orders, then placed each customer’s cup to indicate exactly what the customer wanted...
Common parlance among railroad and aircraft modelers, probably most often mentioned in mass publications in articles about special-effects builders for science-fiction films. Seen with the hyphen, and also as “kitbashing,” and “kit bashing.”
Used in a book title in 1978:
“Scratchbuilding and Kitbashing Model Railroad Stations” by Bob Hayden, Kalmbach Pub Co.
My husband remembers the term from at least the early 1970’s, and I’d expect mentions in the fan press around the time of “Thunderbirds” beginning in 1964
http://www.tvcentury21.com/content/view/212/41/
and certainly in coverage of the production of Star Wars and Close Encounters