I found an image of the Hagstrom J-45. Tailpiece and tunamatic bridge as you described, but now it makes sense. Have a read of this article.

http://www.frets.com/FretsPages/Musician/Mandolin/LtMandoBr/ltmandobr.html

You were right about the improved sound. If you could make, or have made a bridge like Frank Fords your Headway snake could be built into it. If your pickup will fit between the pillars of your existing bridge then a piece of rosewood or ebony or even maple or sycamore could be slotted to take your pickup beneath a convential acoustic sdaddle, and the complete unit placed between the pillars. Lots of options really.