One of my mirrors broke off and is now history... I found these # 91968-98 on the HD website and like them but am having trouble finding out what the dimensions are and what the threads are (SAE or Metric)... If any one has them, I would appreciate some info on them.. Here's what the look like in the following link.. Thanks Bob.

https://www.surdyke.com/PartsMain.as...nted%20Mirrors

 

^^^ FWIW the statement that they fit from 1982, tells me they would go onto My FXRS...and therefor, the thread, which goes into Signal Mounting hardware, is SAE ...5/16-24 in fact If (big word) If they are truthful.
Dimensions... Sorry, I will ask my youngest!! maybe tomorrow...