Andre Engels wrote:
What, if anything, can be done in Wikipedia with texts
and pictures that
fall under the Open Content License (either in original form or one of its
restrictions)?
One of it's restrictions? The Open Content License is pretty restrictive
as is. Perhaps you mean the Open Publication License, which is a free
license, but has two options, which, when exercised, make it non-free.
It's probably best not to try to merge this stuff, unless you can get
the original author to add the GFDL as an adjunct, as it would be too
much of a headache for the vast majority of contributors.