It looks like the Stage Further's have an FJ serial and do not have a back lamination matching the front. Like the difference between a Standard and a Deluxe.
Both examples referenced in the thread (the one featured here on Alembic's site and the one on Reverb) share these traits.
They also have different controls including a 5 position switch with brass plate and one of them has a brass pickup surround.
Whereas, regular Furthers have the same control layout as Tributes.
Also found this:
http://alembic.com/club/messages/393/62726.html?1238618387"Here it is... your "beater" Further :-) Well, maybe that's a little bit of a stretch, but at more than 30% less than the original Further guitar, it might feel more comfortable taking to some venues that a custom Further guitar might be too shy for.
The Further Stage guitar features a friendlier set of controls for live performance. A simple volume and filter control with a 5-way blade switch for fast pickup selection is all you need. To get even more from your outboard effects units, effects loop operation is with a blend control, to mix just the right amount into your sound. " - Mica