I post this dumb clip all the time, but this is a 5153 100w EL34 on the Blue channel with the gain just barely cracked open, like 0.5 out of 10. All stock. There isn't a ton of room on the gain pot to get this kind of sound, but it's in there if you're careful. The Blue preamp of the 100w Stealth is identical to the Blue preamp of the 100w EL34, so you could get this exact tone with the Stealth also, but with maybe very slightly lower mids but you could just turn the mids up a hair to compensate.
The amp settings never change, just the guitar pickup selection and playing dynamics, that's it. Start of clip is an EMG 89 in the neck, coil tapped. Middle of the clip at 1:15 is the 89 neck in humbucking mode. End of clip at 1:58 is an EMG 81 in the bridge.
I made it to show that the amp doesn't have to be a 100% firebreather all the time. Actually I tend to think of the 5153 as a slightly harder sounding, more modern high gain Bogner Ecstasy. I've got a 101B and if I boost it and cut bass at the input, it and a 5150 III are a lot more similar than anybody would think. Like they sound almost the same.
Anyway, I posted this clip here to show that if you can't sell the amp, maybe you can at least use it to fill another kind of gap in the tones available to you.
edit: I also wonder if you could have the amp modded for a different gain pot. The schematic says the Green and Blue channels use 250k pots with log30 tapers, which means at noon, the pot should be set to allow 30% signal to pass through it. A linear pot would allow 50% signal pass at noon. The Red channel uses a 1 meg pot with a log5 curve, which means that at noon, only 5% of the signal is getting through, if you can believ that, lol.
I'm saying that if you want a more flexible Blue channel, you could try to find a 250k pot with a lower log value, which would give you more knob sweep resolution at lower gain settings.