The BAA Memoirs are available on SAO ADS.
https://ui.adsabs.harvard.edu/search/q=bibstem%3AMmBAA&sort=date%20asc%2C%20bibcode%20asc&p_=0
Unfortunately the person doing the scanning doesn’t seem to have worked out the pagination and sometimes the content doesn’t match the title!
Bill Barton,
Deputy Director, Historical Section.