Interesting experiment... I got the Toscanini box set in the recent black friday sale at Amazon. I've had a few of RCA's Toscanini LPs and CDs in the past, but they were recorded in a studio at NBC, not a concert hall, so the sound has almost no reverberation. On top of that, the early digital releases were pretty harsh sounding- overdriven peaks and an EQ that favored the upper mids to the point of pain. The new box is MUCH better, with more balanced sound and no clipping in the peaks at all. The boxiness of the small studio is still there though.
Today, as an experiment, I tried playing one of the most constrained sounding recordings- Berlioz's Romeo and Juliet. They packed an orchestra, a chorus and vocal soloists into Studio 8H. The sound is good, but it comes out and then just stops dead. No ring out at all. So I figured I'd try one of the DSP settings on my Yamaha receiver. First I listened to a bit with the 7 channel stereo setting. That opened it up considerably. Great separation of instruments. Then I tried the two concert hall simulations- Berlin and Vienna. A revelation! It wasn't true stereo because the violins were in the middle, but the transparency and most of all hall reverberation were outstanding. I've never used this setting before, because a synthesized concert hall over the top of another concert hall in the recording just gets too thick. But for this application, it's perfect.
I wish it was as simple to record 5:1 sound as it is stereo. I'd run the whole box through the DSP filter and burn it onto a blu-ray disk.