Texas Tech Vietnam Archive

Folks may be familiar with this but I have found it to be a wealth of information!

Texas Tech Archive

Yes, probably the best out there in the interweby-thingy

I have used it various times in the past but had forgotten the link.

may I offer here for maps http://legacy.lib.utexas.edu/maps/topo/

scroll down to the bottom of the 'ASIA' section and you will find the 1;25000 , 1:50000 series of maps , and particularly checkout the 1:250000 'Joint Operations Graphics; (JOG). .. check the dates of some of these ; some of them are from the period. The 'Saigon' JOG was published in 1983 from data from 1972. These save easily as a pdf .

also https://www.cia.gov/library/readingroom/collection/vietnam-collection

for some light reading and analysis . also of interest ; the 'Air America' archives via the left column tabs.