I know it aint much, but hey - its my first build in a 1590 enclosure! Hardly defines as stompbox, being an eight-ohm 100W resistive power attenuator for my tube-amps. An isolated output jack keeps the doctor away. (http://img.tapatalk.com/d/14/06/04/ejupemuj.jpg)
Must add that it does not handle 100W in this configuration. Would need a heat-sink. Contains 50W alu encapsuled 8 & 4 ohms resistors.
Congrats on the build! Looks like it sits nicely in the amp.