[analog what is that?]

You know, recently I released a 2 disk DVD set for sale about Emulsion Making and Coating.

Now, this is not a sales pitch it is a story about making the DVDs.
...........
The point of this? Computer files seem to become obsolete or contain many errors which makes it difficult to work with them over a time base that is probably on the order of 5 - 10 years.

PE

thnx for the sales pitch .-)

Nope, this is not a problem not for us that spent the 80's and 90's mostly buried inside computers.....
Most of your file-incompatibility issues are solved quite easioly by one piece of software : ditch those MickeySoft programs and move over to opensource SW, personally I have fled ship and uses OpenOffice this SW will let me open PDF-files, most backward compatible SW I have, It will let me edit and save PDF-files, open more MS Office files than Bill Gates ever wanted and ask no questions. And it will let me save files in umpteen formats that mickeysoft haven't ever heard of....

In other words its your responsibilty to keep up with the times, I have never had problems like you describe.