My footswitch was in the little cordura (mine isn't vinyl, the reverb tank pouch is vinyl) pouch attached to the side (inside) of the cab. The pouch can be removed, I took mine out because I was doing speaker experiments. The reverb pouch is easier to remove if you take the little 1/3rd size back panel off, but don't mess up the sticky gasket thingy that keeps the panel from buzzing.
EDIT: Sorry, mine is the 5.25, probably different than yours in these matters.