I tested this booting "tc base norestore nolocal", creating a folder /tmp/test and copying gimp2.tczl, gimp2.tczl.dep, glib2.tczl, gtk+-2.tczl, expat2.tczl, fontconfig.tczl, graphics-libs-1.tczl, libxml2.tczl, ttf-bitstream-vera.tcz, gegl.tczl, librsvg.tczl & libwmf.tczl to the folder.
Note that I should also have copied libxslt.tczl, lcms.tczl, libmng.tczl & poppler.tczl to /tmp/test, but I couldn't find them from the command line, so I removed them from the local copy of gimp2.tczl.dep for the purposes of the test.
I loaded gimp2.tczl from /tmp/test using the app browser and, although it complained about the missing libs, it worked: $ gimp &
LibGimpModule-Message: Module '/usr/local/lib/gimp/2.0/modules/libdisplay-filter-proof.so' load error: liblcms.so.1: cannot open shared object file: No such file or directory
LibGimpModule-Message: Module '/usr/local/lib/gimp/2.0/modules/libdisplay-filter-lcms.so' load error: liblcms.so.1: cannot open shared object file: No such file or directory
LibGimpModule-Message: Module '/usr/local/lib/gimp/2.0/modules/libcolor-selector-cmyk.so' load error: liblcms.so.1: cannot open shared object file: No such file or directory
/usr/local/lib/gimp/2.0/plug-ins/file-jpeg: error while loading shared libraries: liblcms.so.1: cannot open shared object file: No such file or directory
(gimp:4552): LibGimpBase-WARNING **: gimp: gimp_wire_read(): error
/usr/local/lib/gimp/2.0/plug-ins/file-mng: error while loading shared libraries: libmng.so.1: cannot open shared object file: No such file or directory
(gimp:4552): LibGimpBase-WARNING **: gimp: gimp_wire_read(): error
/usr/local/lib/gimp/2.0/plug-ins/file-pdf: error while loading shared libraries: libpoppler-glib.so.4: cannot open shared object file: No such file or directory
(gimp:4552): LibGimpBase-WARNING **: gimp: gimp_wire_read(): error
/usr/local/lib/gimp/2.0/plug-ins/lcms: error while loading shared libraries: liblcms.so.1: cannot open shared object file: No such file or directory
..but now I see the problem - lcms.tczl and libmng.tczl do not exist, and libxslt-1.1.24.tczl needs to be renamed to libxslt.tczl (or I need to rename it in the dep file).