Just an update - I have an appointment to take the painting to the framers on monday for them to remove if trom the frame. They'll store the frame for me, so I just have to bring the painting home, varnish it, let it dry for that indeterminate amount of time, then take it back and they'll reframe it. They said "for a nominal fee."
Nominal is such a subjective thing, isn't it? One woman's nominal is another woman's astronomical, I always say.
No, really, I do.