Upcoming galois release

Hello,
I'm working to release a new upstream version of Galois and update the
Debian package (I'll need sponsoring as usual).
Can you please help me deal with a few Lintian errors/warnings:

E: galois source: source-is-missing [doc/galois-it.html]
E: galois source: source-is-missing [doc/galois.html]

That simply isn't true. The source files are there and are
doc/galois-it.xml and doc/galois.xml. The html files are generated
simply by running "make html" in the doc directory.
How can I let Lintian know?
Note: in order for "make html" to work a few additional packages need
to be installed, namely: xmlto, dblatex, texlive-lang-italian. I
didn't set them as build-depends because they aren't needed for
building the package ("make html" isn't run during the build). Perhaps
I should?

W: galois source: inconsistent-appstream-metadata-license
misc/galois.appdata.xml (gfdl-1.3+ != gfdl-niv-1.3+)
[debian/copyright]

As far as I understand GFDL-NIV-1.3+ is the correct string to put in
debian/copyright (please correct me if I'm wrong). I tried to put that
in misc/galois.appdata.xml too, but it doesn't seem to be accepted as
a valid option (appstreamcli bails out on it). As things currently
stand, I guess I should just ignore it. Do you think I should file a
bug on Lintian?

I: galois: extra-license-file [usr/share/gnome/help/galois/C/gpl.dbk]

I believe I should just ignore this. The file is required for the
Gnome documentation (doc/galois.xml, doc/galois-it.xml) to be
self-contained. It's been there in every release.

I: galois: possible-documentation-but-no-doc-base-registration

Since this is only info-level warning I might ignore it, or do you
think it's important? If so, can you please suggest what I should do?

Another issue: my GPG key was originally set to expire in 2021. I've
extended it to 2024, but I haven't used it since. Can you please check
that it's ok? The key fingerprint is AAC6 4CF6 8354 826A D78D BD4C
27E3 7504 8FDB 4BC9.

Thank you
Gerardo