Try and Advance Search and you should be able to find:
[1] a link to a guy who photo'd the insides of a UA5 in excruciating detail
[2] a post from Todd about which op amps may be used as replacements to achieve a more Grace-like or Apogee-like sound, per a casual posting by Doug Oade
Don't know of any actual schematics, though.
Not sure exactly where they are, but give it a go. If you don't find 'em, lemme know and I'll see if I can dig 'em up.