Jerry Only's Bass

Jerry and Doyle build their own instruments and amplifiers. IIRC, their father owns the Stihl chainsaw company, so they have access to all of the equipment they could possibly need.

 

Currently, they make all their own. Before this, they usually made all their own. It's more than likely Jery saw a spiky Rick he liked, gutted it, painted it black, slapped his EMG model Ps in there, and played it for a while...

Also, back in the day, Jerry and Doyle went through a lot of instruments at shows, smashing them to be cool. They'd play something random for half a set, destroy that, then pull out their customs to finish off.

 

Bah. GCG used to have a thing in their FAQ about the 'Fits making their own stuff, but I guess that's changed in the past few months. The GCG website DOES say that he won't make more Misfits instruments without the consent of the band, however.

Edit: From misfits.com:
Aside from an inventive approach to music and its visual presentation, their all-encompassing DIY mentality was and continues to be their strong suit. From their Misfits compound in the far reaches of North Jersey which includes even a family owned machine shop business, they craft their own instruments: guitars and bass down to the studded leather straps and even their spiked leather jackets. Creativity rules as they design and construct on site their own elaborate stage sets and wide array of infamous props.