Roland-Ready 7 String...
There's apparently a work-around for using Roland V-gear and synth gear with a 7-string that may or may not meet your needs. *Apparently, according to a guy named John who plays custom Conklin extended-range basses for a band called "Lord Only" <www.lordonly.net> <www.conklinguitars.com>, if you simply wire two strings to 1 input on the Roland gear, if you don't play double-stops, but only play one of the two ganged strings at a time, there's no problem. *Of course, you'd have to play around the limitation, but it would still add some utility. *The wiring took place at Bill Conklin's shop, so someone there is apparently familiar with the details although I haven't talked to them since learning this from John.
There's something I hope you guys can help me with in my own quest for a midified Ibanez baritone with piezos and 13-pin output: I need the dimensions of the 1017XL bridge saddles, ideally a good diagram, but I would welcome partial information, even the approximate length and width as measured while installed in a guitar with a finely-marked ruler. This would start me on the parth to finding some piezo saddles that might be modified to fit the 1017XL.
Another piece of information that would help would be from someone familiar with both the 1017XL and other models with a similar bridge: do the saddles on the baritones appear to have the same dimensions as the saddles on the other models? *If so, perhaps I could at least track down an instrument with the saddles as used on the 1017XL at a local dealer so I can get a close look and measure for myself.