In an attempt to produce the modular firearm "Man From U.N.C.L.E." producer Sam Rolfe envisioned for the show, toy makers were consulted for inspiration. Their first offering was patterned after a 1934 Mauser modified with an extended barrel, telescoping stock, scope, suppressor and extended magazine.
While some were satisfied with the look, others said the pistol looked overwhelmed by all the attachments, compromising its aesthetic and photograph appeal. Regardless, the gun made its debut in the second episode ("The Iowa Scuba Affair") where it failed to function reliably despite the use of extra-power blanks. The added weight of the carbine attachments were the suspected culprit. Prop masters Bob Murdock and Arnold Goode scrambled for a replacement gun. They didn't have to venture any further than the nearby sound stage of the television series "Combat," where they borrowed several Walther P38 pistols.
The prop crew eventually developed a second variant of the U.N.C.L.E. special using the Walther P38, patterning it after the original finicky Mauser. They also experimented in converting a few of the borrowed pistols fire full-auto. However, due to the internally threaded stem found on the extended carbine barrel the new creation was made to fire blanks only.
By 1965 NBC was receiving letters at a rate of 10,000 a week. But, fans weren't only intrigued by the actors, roughly 500 letters dealt with the U.N.C.L.E. Special. Apparently the series fan base also included employees of the Bureau of Alcohol Tobacco and Firearms (B.A.T.F.), because MGM was eventually fined $2,000 for manufacturing a fully automatic weapon without a license.
I modified two P38s for my project, making one a pistol version of the U.N.C.L.E. Special, while the other be is destined to become the carbine pending (B.A.T.F.E.) approval.