In the 40's and 50's EF Johnson, Hammarlund, National, Cardwell, Millen, etc., would have ads in QST and essentially a small part of their catalog in the advertising section of each ARRL handbook.
The information was at best summary, but it showed their major capacitor lineups and common capacities/voltage ratings.
More complete sales-based listings showed up in the 50's Radio Shack, Allied, Newark, Burnstein-Applebee's, etc., catalogs.
Many of the above can be found on the web. For example 1951 Radio Shack catalog: http://www.radioshackcatalogs.com/catalogs/1951/
pages 130-132 has National, Millen, and Cardwell capacitors.
Each company also had 3-hole punched pamphlets with more complete and technical listings of their product lines, I had some of these 35 or 40 years ago, but wow that was a long time ago. I'm sure I don't have them anymore.