drupal contextual filter (URL argument) OR operator
Can different content types share a common field?


In drupal 7 (maybe also in drupal 6) yes you can.
When you add a new field to your content type, you've the possibility to add a field that already exist: "Add existing field".

Then filtering on the field should work for any content type using it.

Basically, I would add to the three content types Books, Photos and Article the same field "field_issue_number".

I think that will make your life easier :)