Barrister Bookcases/ Globe-Wernecke

Hey guys, I have been hard at work on restoring my bookcases and have run into a slight problem. My Grandfather had at some point in the past (20 years or so) glued several pieces of old paneling onto the back of the sections to reinforce the cracked veneer. I have removed the paneling, and discovered that the wood backing is actually cracked into sections with wide gaps.When seen from the front, it is not noticable, but I want to know if I should fill the gaps with a wood putty or leave them be? On these 2 sections I am not going to worry about "value" to much as I am more concerned about the being able to use them. The other thing is, what can I use to remove the nasty Elmers Wood Glue that remains?