Some information for anyone who had trouble finding the parts to make your own FS. I easily found the schematic within the amp schematic, but no values for the diodes or LED's. Being an Extreme Hobbyist, and not caring about maximum smoke, I went for it. Here's what I used:
NTE PN: 5141 30v/5 watt Zenner Diodes.
Linrose PN: B4302H5 5v Super Brite LED [green] B4302H1 [red]
NTE PN: 54-136 SPDT switches. Actually, any single throw latching switch will work. It's just on or off.
These brands are what my local store carries.
I used a 1/4" Mono jack that I had laying around. Standard guitar part. I made a little box from some scrap metal.

Follow the diagram that Fender provides for polarity [bias] of the diodes. Viola! It worked! This is for the models that use a mono plug. Not a TRS style.
I searched everywhere for the diode spec. and couldn't find it. I think I breezed past the 30v/5watt mention somewhere, but I can't remember where. But those numbers stuck in my head.

Keep in mind that I'm insane. DO THIS AT YOUR OWN RISK! But it seems to be working so far.
Just thought this was good info. Have fun! Jimbo
Oh, thank you Fender for being nice enough to release the diagrams to us! They have darn near everything you could ever want, right there.