Strange GD volume pedal issue

[mmaatt25]

Hi,

I recently got a used George Dennis Stereo volume pedal.  I only needs a mono pedal but it was so cheap and as I can use it mono anyway not really an issue. It's appears to be an older version with the left, right and minimum volume controls all on the righthand side. There's no model number eg GD25 etc just PA-950-075 and on the front PANORAMA STEREO VOLUME!
When I plug in either the power jack (big muff style 1/4 inch jack) or the input/output jack, I have to do it really slowly or the indicator LED illuminates then goes out.  If I do it slowly and keep the LED illuminated it works fine except the minimum volume pot does nothing. If I plug it in so the LED illuminates and then goes out it works fine and the minimum volume functions as I would expect. It must be getting power under both circumstances as when it turn the power off its dead! Whats going on!!

One other trivial thing, I got a EHX Small Stone Nano (EH4800) phaser yesterday, which I like alot I must say, but I noticed that the colour toggle switch is missing it's securing nut, as it's used I thought maybe the chap I bought it from had had it apart from some reason! However a quick google image search revealed quite few with this nut missing! Quality assurance issue? I know I might seem very anal, but these nuts serve a purpose even on board mount switches and pots. The nut is definitely 5mm so M5 but the thread is not a standard metric thread it is very fine. I've searched high and low on internet and my stash of nuts and bolts to no avail. Any ideas of where I can get a nut from.

Any help appreciated
Matt