The modif.scm file should be a straight CVS export from http://ssax.cvs.sourceforge.net/viewvc/ssax/sxml-tools/modif.scm and the tests/vmodif.scm should be an export from http://ssax.cvs.sourceforge.net/viewvc/ssax/sxml-tools/tests/vmodif.scm

Any hacks or patches should go into the chicken-specific file sxml-modifications.scm