> how did authors handle symbols?
Mostly they didn't .. it was handballed to the secretaries of the math and physics typing pool who used stencils, high end typewriters, and other template mechanisms.
A good many such secretaries were reasonably talented math and physics graduates themselves who had limited opportunity to be hired to do "a man's work".
When I was a grad student at the Institute for Theoretical Physics in Heidelberg in 2014, they still had a few of these secretaries who would type out handwritten manuscripts by professors who couldn't or wouldn't write LaTeX. Maybe they still do.
Non-secretary women were not in short supply at NASA at this time though. The work of Virginia E. Morrell and Bonnie J. McBride a few years earlier, at this same research center springs to mind.
There were some to be sure .. I wouldn't imply otherwise, none the less many existed that were not hired and most STEM heavy companies and institutions were very male biased.
(With the few and obvious exceptions such as Dame Vera Stephanie "Steve" Shirley's ventures)
FWiW I learnt a wee bit from Cheryl Praeger, Cathleen Morawetz, Robyn Owens, et al.