Maestro Phaser TBP mod??? (problem with bypass)

[Sindran]

I have weird problem with my Maestro Phaser:
It's on pedalboard with bunch of other effects.
Sometimes when I turn on Fuzzface (before phaser) signal gets really low.
Stomping couple times on the phaser usually fixes the problem.
So it only happens when Fuzzface is on and Maestro is off, but not everytime.
...Strange?

I was planning to do a TBP mod for Maestro, and maybe add LED (on the backplate) while I'm on it.
BUT, Does TBP switch fit inside that funky maestro box? (the one with balls and speed knobs on sides)
Has anyone done anything like this??? I wan't just to change the original swithc with TBP-switch. I don't wan't to do any radical changes to this old unit...

I was planning to open it before I start posting here, but that box is so difficult to get open!!!
I need to buy right sized hexkey. I have metric set, and I probably need Americansized key to get it open.