Another little detail, and this one's important- - - - -the grease cup fitting that's in the side of the housing has a spring and a plastic disc under it that puts pressure against the distributor shaft and keeps the shaft from wobbling. That wobble can affect the point gap and result in a rough idle due to timing changes between firing impulses from one cylinder to another. If the disc is missiing or worn out, the spring will wear a groove into the shaft. A small slice of 5/16" phenolic plastic round rod like Bakelite or Teflon makes a good replacement.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!