[A/S] Recalcitrant toilet seal

["Lee Gilchrist" <LeeGilchrist@xxxxxxxxxxxxx>]

A couple of months ago we had a freeze here in western WA.  I have a 1975 29' 
International that I wanted to winterize a bit with antifreeze, and when I went to flush 
the toilet, the sealer disc that moves aside to let the water flush down got stuck a bit, 
then with just a bit of coaxing (prolly a mistake) it opened, and stuck in the open 
position.  Even after thawing it still doesn't come to the fully closed position.  I'm 
reluctant to fiddle much with it, for fear I'll worsen the situation.

How do I free it up so it closes naturally?  It's been thawed for a month or so now and 
still won't close.

Thanks for any help.
Lee