mantle clock "silent chimes" lever interfering with chimes?

I have a Herman Miller mantle clock c. 1940's that's been in the family since new. In researching getting it going again (after many years of silence - yes, I know it will need cleaning and re-oiling) I'm finding that at each quarter hour it starts/tries to chime but the silencing lever is "lifted" and interferes with the fall of the last two hammers. It will allow the "hour" "bong" to chime but I can not seem to affect its movement, nor have I seen any comments on the web concerning this problem. Moving the "silencing" lever to "off" does not silence any of the chimes so I am suspecting that there is something off with the mechanism inside ... though the clock hasn't been fooled with or taken into a shop that we can remember. It has been involved in moves but the pendulum was padded and "locked" and the clock was moved carefully. Any help with this problem would be greatly appreciated. Thanks!