Reverting to an old version in a branch

[M.M.]

(What the hell is going on? Only the first sentence appears! Let' try
again without paragraphs.)

The package "gnome-shell-extension-weather" is currently in the f-16,
f-17 and f-18 branches. From a recent update onwards, it seems that
the extension has lost compatibility with Fedora 16 (please see this
bug report: https://bugzilla.rpmfusion.org/show_bug.cgi?id=2564 ). Is
it possible to revert the package to an old build (the last compatible
with F16) in the f-16 branch and then make such branch (and only that)
stick to that version in the future? If so, how to do that?

Thank you in advance.
M.M. (odysseus)