I have (may actually be had - I haven't looked yet) the schematic I used for my strat...What you'd get with it is regular wiring with the push/pull in the down position, and then when the push/pull is pulled, setting the 3-way to the bridge will yield no signal at all, and the other two positions will give you bridge+neck in series
Plus side is that you get a killswitch effect as well - down side is that if you're not paying attention, you could end up accidentally switching your guitar off...
There may be another (better) way to wire it, but I came up with this myself for my strat and it was the only way I could see to do it...let me know if you want me to find it for you
EDIT: Slowhands in series sound awesome :D