Around the time he retired, David Bright scanned a large set of old Microbeam Analysis Society proceedings. He scanned the old EPASA meeting proceedings starting in 1966 and when EPASA became the Microbeam Analysis Society he scanned those until 1993. So we have a full set of meeting proceedings which, a couple of days, ago I uploaded them to the Internet Archive. I've created a page on the MAS website
https://the-mas.org/historical-microanalysis-meeting-proceedings/ with links to each of these.
Now for 1994 and 1995, for these years we switched from the small company "The San Fransisco Press" to VCH (which is now VCH-Wiley). About a decade ago someone on the MAS council asked the widow of the founder of the San Fransisco Press about whether we could scan and share these proceedings. As I recall, she said yes. Nothing ever happened.
VCH is another story. They don't seem to be available on the web but we don't have permission to share them. Since they are a large company with nasty lawyers I'm a hesitant to just scan, upload and link to them.
In 1996, the MAS returned to San Fransisco Press for one year. (I haven't uploaded/linked this yet but I plan to.)
In 1997, the MSA and the MAS created the Microscopy and Microanalysis Journal which published our proceedings and maintains them online (for free!)
There may be additional subtleties that I haven't fathomed yet related to MSA meetings vs MAS meetings. I just notice that there are two distinct 1993 proceedings - the San Fransisco Press one online is the MSA meeting and there is also a VCH one for a distinct MAS meeting. I guess this was before they were joint meetings.
TLDR;
1966-1993 are available here:
https://the-mas.org/historical-microanalysis-meeting-proceedings/1994-1995 are troublesome
1996 will he available at
https://the-mas.org/historical-microanalysis-meeting-proceedings/ when I get around to it...