@GeoffR: A quick glance at stuff with a 44px size (both in zlib streams and in literals) indeed yields quite a few things. Some stuff can easily be discarded as "probably not it" given the context, and I was indeed afraid what was left would be one of those spacers, which do look like they might be used in quite a few places...
I hadn't yet gone around to actually try it though, so all of this was theoretical so far

.
But I'll see how that behaves tomorrow, thanks for keeping at it!

.
EDIT: Out of curiosity, besides this example, has anyone tried any of those other ones? (Ideally so I don't spend my time testing stuff that someone already checked

).