Ciao Brian,
Fredrik will surely answer soon and I just try to help a little, if I can...
I don't know if there are planned implements in this direction although I remember old discussions about Dewey & LCC.
If it can be of any interest, I know that the latest BookCAT version can query the Library of Congress by the LCCN number...
BookCAT can internally create a lot of different Labels with ANY database field you need.
It seems to me that the whole Avery Labels catalog is supported and you can create your own labels too...
I remember old "copyright" issues about that, but I don't know if something is changed in the meanwhile.
If that can be done, I'm sure that Fredrik will give it a closer & thorough look..
Hope this helps & have a nice day ! :D