Grace/Big Daddy Combo question

[mydementia]

Hey guys.
I'm messing around with putting the Grace and Big Daddy 386 circuits (ROG: http://www.runoffgroove.com/grace.html) in the same box and am not sure I have all the logic down.  Here are a couple snapshots of my layout:


My thought was to share pots.  As shown above, I'm using an SPDT to direct the input signal.  When I fire it up I get a lot of squeeling - and a little distorted guitar in the background.  The Big Daddy circuit seems to oscillate/squeel a lot more than the Grace circuit (makes sense with a gain stage in front of BD).  Both 386s have reasonable looking voltages (compared to my Ruby builds) and the J201's seem to be setting up correctly (drain ~ 1/2 input voltage).

I'm wondering...
1) To do this right, would I need a 3PDT switch where I isolate the input, power, and output? 
2) Will sharing pots actually work if one circuit is unpowered and I/O is isolated?
3) Is there a simple way to make this work? 

Thanks in advance.
Mike

[mydementia]

That'll be a bu-ump...

UPDATE:
I swapped out the SPDT switch for a DPDT to switch both input and output - it's better - bus still noisy as heck and generally crappy.
Thanks for looking.
Mike