Looks OK for me (after wrapping my head around PLIST_FILES and PORTDATA and how the port installs the files).

Keep it at 32bits, only extend the defines to cover visually 32bits instead of only 16 (and keep
the new flag).

In general it looks ok. I haven't validated the plists or such. The Mk files look good (no obvious error). The rest seem to be "a simple version update".

That's where patching the current ports tree fails. I've tried to fix it, but it seems to have been generated from your previous patched ports tree.

After agreement with Alain: comandeer this revision.

I improved some parts of the code (see individual comments).
As it seems phabricator is build for more colaboration between the people besides 1 submitter and several no-patch-modify-rights reviewers. It doens't allow me to upload my diff.

Answer a question from eadler.

I have reviewed this completely (read-only, I haven't tested anything) now (Essen Hackathon 2015), and apart from the comment about the remvoed IGNORE part which should be handled, I think the patch is OK.
Is this tested to not break the 32bit version of the linux base ports (c6 & f10)?
If it doesn't break -- specially the case where a port wants c6 but the override is set to f10 (= the IGNORE part of my comments) -- I would say go ahead and commit it (it will not hurt to have some rough edges in the 64bit parts... if any, we can fix them as they show up).