Quoted from Jeekayjay:Thanks!
I had to open it up all the way to allow for maximum clearance and still have to push down fairly hard but she's firmly in place now!
With my newly installed fully functioning replacement book as well I'm ready to rock!
It's buried in the thread somewhere - remove the 2 screws that hold the lockdown bar assembly to the front of the cabinet and then loosen the 3 nuts. There is some play in the mounting of the lowdown bar assembly with the nuts loosened. Put the top of the lockdown bar assembly flush with the top edge of the cab and retighten the nuts. The screws likely won't go back into the existing holes and can be left off.
That's what I had to do with mine the first time I took the lockbar off, and several others have had the same issue.