Spent the last months of my life working on a Deluxe Plus - basically an amp built around the complete Reverb channel of a Deluxe Reverb amp. It has lots of added goodies including a really different-sounding cascode preamp (instead of the Normal channel). Check out details here.
The amp looks like a DR at first, but when you look closer... it's clearly not. Given this experience, I have to say that the DR makes a great platform for a novel amp design. Would love to hear from people that have had any similar projects or experience with cascode designs.