It took a while, but someone finally came up with a production-model electric mandobass. At least that's what the Morgan Monroe "F bass" looks like to me. Features include all solid wood construction, maple back and sides, spruce top, maple neck (about 1.5" at the nut), adjustable truss rod, dot-inlaid rosewood fretboard, 30" scale, adjustable rosewood bridge, sealed die-cast tuners, trapeze tailpiece, gloss sunburst finish, built-in bridge transducer, and onboard volume and tone controls. Like all Morgan Monroe instruments, it's imported from Asia.
You wouldn't know any of this if you went to the Morgan Monroe Web site, because the instrument isn't listed there. I can't imagine why not—I mean, a mandobass is nothing to be ashamed of.