I'm sorry for the missing information. The action in the piano is an
Autopiano. It's like a standard in about every way except pump design and
valve style. Instead of the valves being on metal stems held on by force fit
collars ( standard ), they are "screwed" onto threaded stems and travel is
adjusted by pushing in and turning the stem either clockwise - for more
travel, or counter-clockwise - for less travel. Yes, you are correct. It
does have a double valve action.
        Thank you Les for your tips on finding the leaks. I shall do that
immediately.

                                                                Jason