PomDave:You have encountered the same delimma that has confronted stamp collectors and postal historians since the day the second stamp or cover was encountered:
"What exists?"But no one else has wanted to look at the data in the same way that you do, because you are unique, and look at things from a different point of view.
The solution is the one that countless collectors have taken:
"Create your own catalog." 
So, get out your trusty Spreadsheet, and start tabulating information. The following is a simplistic approach, but you should get the idea:
- Create the list of stamps of interest by country
- Record the catalog numbers for the stamps with the numbers used in your catalogs
- Add any descriptive information you desire
- Create a column for the "official" release date if available from the issuing Agency
- Create a column for the release date associated for each catalog or other source.
- Start recording dates
- Perhaps start a column for unofficial sources for the release date, like newspapers or philatelic publications, especially if they show a date different from the "official" sources. Add a column to record the source.
- Look for First day covers if they exist
Eventually you will find a pattern, who has the best information, the most consistent information, etc. But in the long run, it is YOU who will have to decide what is accurate and reliable, and who is not.
Then help out the philatelic world, share and publish what you learn.
That's the nature of the beast.
Good luck, and enjoy.


Mike