Sorry, but I think you are going to have to pull the valvebody, flush it out while moving the valves back and forth to make sure they are free.
Then very probably have to pull and rinse the governor also. (maybe do this first as it couldn't hurt) then try it, before you pull the pan and have to drop the fluid.
What is worrying us a little is we wonder what was in the fluid that settled out while sitting enough to cause a valve to stick in it's bore.
The contents of the pan when you pull it will be interesting.
A little metal and black junk is ok (like a teaspoon)
The reason I say "we" is because Tracy and I have been discussing the possibilities via PM.