Most records I know of were non-specific about the recto being a 2 or 3 channel model. Surely there's not a world of difference between the two? My experience lies solely with the 3-chan, which is a great amp. Possibly the very best rhythm guitar amp I've ever heard.
I'm also not sure I know a single long-time engineer who would be bold enough to say that they can get everything one particular gear chain is capable of. There are always different approaches. I would not sell a Rectifier until I got Nickelback-quality tone with it or unless I got tired of the tone. Because at the end of the day anything less is a failure on my part, not the amp's. I suppose that's where I'm coming from and struggle a bit to see the other side, but if you feel exploring the curiosities will be worth it, by all means, I was mainly just curious.
FWIW I've been tracking peaveys, mesas, engls, soldanos, bogners etc. professionally for half a decade and I wouldn't even dare to imagine I knew all the tonal possibilities that could come from those amps. Believing you're at the apex is very dangerous and counter-progressive, IMO. But I suppose that could make a good discussion for another thread. Sorry for the derail! (though you kinda deserve it after my 'reamp' thread
)
Good luck with the sale.