That was the EXACT model toilet in my folks master bath back around 1979. It was in harvest gold. I remember it being the quietest, most comfortable toilet ever. Cost around $500 back then.

I know that the toilet in the master bath of a house we rented in 1989 was a low-boy but can't recall the manufacturer.  It was silent, which was a nice feature since the master bedroom was small and, as Dave used to say, it was almost like sleeping with your head on the toilet.

That toilet's valve needed to be replaced, as it often allowed a slight trickle of water to run (the flapper wasn't the problem), but the valve was made of china and prone to breakage if messed with, and replacements were no longer available back in 1989.  The only option would have been to replace it with a standard type of valve that wouldn't be silent, so we lived with it the way it was. 

I remember when researching the type of valve needed, reading that toilets of this design couldn't overflow.  If these were still made today in an elongated model and, even better, wall-mounted, I'd consider them.  My guess is that silent operation can't be achieved with 1.25 GPF, though.

Allen, I'm betting that Urban Ore in Berkeley has one of these in their expansive outdoor array of bathroom fixtures right this minute.  I haven't been there in quite some time, but will check on my next visit.

As I recall, with the low-boy no-overflow system, you could swish around the water in the tank and it would cause movement in the bowl.  I never quite understood how it worked but found it odd that there seemed to be no positive separation between water in the bowl and the tank.

Maybe there's a diagram on this somewhere?