Books are forever
The manuals you have are good forever. The early chapters of almost all manuals contain descriptions of and instruction on the loading process. This has not changed much at all in the past 90 to 100 years (since the popularity of smokeless powder supplanted black powder). So, read those chapters of the manuals you have first. Reading different writing styles will broaden your view and expose you to different areas of emphasis.
Having a mentor, you are miles ahead of most beginning reloaders. Lucky you.
The load recipes in the older manuals should be checked against newer manuals, as the formulations of propellants (gunpowders) have evolved over the years and more modern measuring methods have suggested changes for reasons of safety. ALWAYS compare load recipes from different sources and pay attention to the test gun from which they were fired. Every ballistics lab is different.
The 505 and the MEC are well worth the entire purchase price. Your wife is a good shopper.
Congratulations and welcome.