Federal doesn't show the GUTR kit as valid (the individual hooks are), but David P. posted a Gall's link over on .org and they still have them.
http://lightbars.stores.yahoo.net/fedhookonmou.html
I also have a parts list if anyone needs PNs for the rubber feet or assorted hardware. Some still show as valid in Fed Sig's system, but some do not. You'd have to call them to see exactly what is and isn't available anymore.