" By my calculation, you can drop the volume to about -34db in low gain mode "
The 0.5 stepsize is for the upper 2/3 control range of the volume dial. At the lower part of the range stepsize is somewhat larger. The minimum amplification factor is actually somewhat lower than that of the 2STEPDANCE.
"Does this mean it is ready to be ordered, or is this just the information?"
If all goes well the amp will be available in 1..1,5 weeks. Of course it's well possible to order right now. Who pays first gets served first.
"I'm seriously interested in what the Classic will do with its extra power and whatever else Jan has improved."
The increase in power is very limited. That's really not a big thing. Soundwise the more important differences between the CONCERTO and the CLASSIC are the use of better electrolytic capacitors (NICHICON Fine Gold instead of NICHICON FW, resulting in a slightly warmer sound with better definition in the low frequencies) and the implementation of a more sophisticated crossfeed filter which has better imaging.