Vintage Tin Litho Metal FRICTION SPACE GUN Korea MTU Shudo Japan Blue Red sciFi

Vintage tin-litho friction gun. About 5.5" long and lightweight 3 oz. The viewing window at the end suggests this toy should make sparks, but it doesn't. The trigger works excellently and all the noises are there, so I think just the friction/flint mechanism needs replacing or refurbishing. The gun is marked "MTU Made in Korea", but the same gun was also produced by Shudo in Japan. Cosmetic condition is pretty good. There are occasional scratches as well as some paint loss mostly along edges, but overall in exceptional condition for its age. have not been able to find a solid year of manufacture, but seems likely to be 70s.