I don't think flats are the answer here. I can't help but think they would take all of the "gurgle" out of the sound.
Toaster/horseshoe
Flats can do more than "Motown Mud"Haha! Don't say that! I have a v63 that I am continuously battling myself to not modify by replacing the mono jack with a stereo.
Maybe I could get a horseshoe and toaster and put it in something else to try it out...
Here is my old V63 with an old set of Chromes on it:
This recording, too: