There was a joke in Soviet Union: Americans stole plans for super secret soviet stealth fighter. Every time Lockheed-Martin engineers try to replicate the desi

There was a joke in Soviet Union: Americans stole plans for super secret soviet stealth fighter. Every time Lockheed-Martin engineers try to replicate the design according to documentation they end up building steam engine. So Americans kidnap one of the Soviet engineers to help them to decipher the design. Once he sees the documents he points at the small remark at the very end: to get the desired device after building a steam engine shape it manually with a file. This joke is a pretty accurate description of the state of precision manufacturing capabilities of USSR. Manually created single prototype is not a "complex thing that worked".