Look on rec.audio.tech for Richard D. Pierce. He used to modify Revoxes (did one for me) and might be adventurous to try if you sent him a plane ticket. He's a smart guy BTW.
Know anybody who mods analog r2r tape machines?
I've obtained an old REVOX/STUDER B77 MK II together with some Jazz and classical tapes at a garage sale. The sound is amazingly good with a nicely layered soundstage. However the sound is also typically old solidstate, a bit harsh and grainy. Here in its country of origin no tech is interested anymore in this old stuff and wasn't the US in the old days called the "country of infinite possibilities" to those who dreamt of leaving the old continent? Wonder if this still is so....