I had a Shergold 4 / 12 a few years ago. Loved it. Used bass pedals when I played the 12 string. Very versatile but incredibly heavy, infact, it was heavier than a heavy thing that was really heavy. I could only play it for about an hour before it wore a giant groove in my shoulder.
Played quite a few venues where just one 'new' neighbour complained and messed it up for everyone. If you move to, or buy a house next to a pub or a club then you know what to expect and shouldn't be surprised.
I would have thought that all the cabs would use the same drivers so why not just use the 2, 1x10s with both amps? Easy to check, just whip the speakers out and have a look.
Some info about F.A.L. here, http://www.karillon.com/fal.html and here, http://forum.speakerplans.com/stuff-from-the-early-days-roger-squires_topic28079.html and an advert here, http://www.vintageguitarandbass.com/adDetails/235