Interesting that you got a notification today. Estes has been hosting their back catalogs on their web site for several years now. https://estesrockets.com/catalogs/
This page did get revamped relatively recently as part of a greater effort to re-do the Estes web site. Just about all Estes catalogs from 1963 through 2020 and some Centuri catalogs are available at the link above.
My favorite issues: My cousin had a 66 catalog and I loved drooling over it when I was at his house...68 was my first Estes catalog (our local hobby shop carried Centuri -- hey it was in Arizona, what can I say ) ...69 was my all time favorite (love that the 2019 issue has a Saturn V on the cover as well)...70 just looked so cool, and 71 was an artistic masterpiece!
70 and 71 are also my favorite catalogs. The RocTronics catalog of 72 also intrigued me. But alas it was during that time when most rocketeers abandon the hobby for different pursuits.