Supreux Deux prone to Oscillation?

[thehallofshields]

I've been trying to come up with a 4th control for the Supreux Deux. Almost everything I do to increase the gain introduces oscillation.

-- I've tried putting Q2's Bias pot external, turn it below 2/3rds rule with the gain up: oscillation.
-- I've tried adding an "Emitter Degeneration" style Gain control like in Subdecay's Liquid Sunshine (very similar circuit): oscillation.

I'd like to determine if it's:

a.) The circuit design
     The lack of NFB in any of the stages seems like it would contribute. I tried adding a Miller Cap to the main gain stage (Q2) but even 10p totally changes the sound.

b.) The PCB design
     I'm using a very compact board from JKM. Since the components are so close together, extra off-board wiring might be too much for it?