Got this modified 800, what mod is it?

[zerosadness]

Hi, I just got this amp for only 500€, the seller tell my fist that the amp got 4 input, but only 2 are working and modded with 2 knobs on the back so I thinked about a 1959, but finally it's a typical 2203.
The missing hole was in reality from the Led that fall inside and the non working jack, for a footswitch. My first intention was to put it stock but I will prefer ask if someone know what this mod do. it got a relay (certainly for the footswitch) and some strange wiring, between treble pot and pot in back etc.
I'm sure it's like a double channel mod, but I don't really understand what the pots really do and I can't try with a footswitch actually.

You can see pictures in this folder:
https://www.dropbox.com/sh/6adknremde8a ... XGd1a?dl=0

Thanks for your help.

[darkbluemurder]

From the pictures I can see that a cap has been added to the first gain stage (the red block one) and two electrolytics have been added to the second gain stages. Furthermore some kind of channel switching was implemented. The wiring looks a bit experimental to me. Still I think you made a good deal if the amp is working.

Cheers Stephan