Can anyone tell me what the dark spots on the indices are and if I should have a professional clean the watch?

 

dirt acquired during service? degradation caused by age?

...be sure the bezel is correct for the reference -> http://speedmaster101.com/base500-bezel-identification/

 

Is it mold?

 

Really hope it's not

 

It says the bezel was from 1990 to 1995 which sounds about right for this watch ref 3592.50

 

My only concern are the black spots on the hands as well as the hour plots.

 

A tall tach is that late?

 

Note the lack of serifs on the 7s etc - that's the middle bezel from the '90s, between the vintage DNN and the modern dot under 70

 

http://speedmaster101.com/base500-bezel-identification/

 

As I do not own the book I thought those ended in the mid 80's thanks!

 

Surprising and confusing news... Brought my speedy in to a watch repair shop and the repairwoman said the spots were from normal aging, so no water damage, phew.

However, my watch apparently has an 866 movement, not an 863. Weren't 866s limited in production? How does that even work when 866s run moon phase watches, not speedy pros? I'm hoping she was just out of it and read the fine print wrong w her loupe.

Here are some pics of the movement. If anyone could clarify, that'd be much appreciated.

 

Itty bitty little details!

 

Can't tell by your photos, but the caliber will be noted under the rim of the balance wheel. Likely an 863 rather than an 866.