It's probably 43 year old lubricant that's gunning up the works. Might need a thorough cleaning.
Bingo! Correct answer. I bought one in nearly the same condition about a year ago and the ejectors/firing pins??? were hanging up. All it required was a thorough cleaning by a competent gunsmith and now it works/functions perfectly. While you're at it, ask him to remove the old lacquer from the receiver, and re-do it with Tony's lacquer, as it will bring up the colors in the case coloring.
PS: I tried to post a photo, without success, sorry.