Theres definately something to be said for full track mono in terms of quality , Ive set up one of the two headblocks with a stereo replay head and added the extra playback amp for pre recorded material . It looks like I might as well keep onto my mostly complete second C37 . Maybe if a one inch J37 roller/guide kit showed up it might be worth resurecting in stereo or four channel config. With a DAW the full track mono set up makes a great 'Abbey Road Plugin' effect if you want it ,either from an analog source like mic/preamp with the delay corrected for afterwards, or in the case of material off DAW you can easily run a stereo sub or main mix through the tape in two passes , ok downside its not proper realtime stereo off tape , but you do get all the benefits of the full track width(with no guard bands) which is the icing on the cake . In any case the THD and noise of the digital recording path will dwarf that off tape , so no major downside to using it in a re-amping type scenario either, applying tape saturation per channel in an offline situation.
The stereo heads are a saucy price and dont come up that often , plus theres the question of butterfly or normal config , There is some cross compatibility between the heads of the Revox G36 and the A/B/C model Studers, they will at least mount up on the same threads in the headblock , the electrical characteristics /impedences and inductances of the heads is contained in an Studer tape machine head catalog ,cant seem to find the link just now .