Boss Metal Zone tone controls

[sfr]

Okay, for some reason after work (12 hour night shifts suck) today I ended up trying to learn Slayer riffs (I know, I know - it's a challenge, please don't pick on me - I was trying to play Stones and Hendrix yesterday if it makes you feel better) - mostly to play with my Boss Super Pitch Shifter in an attempt to emulate the two guitar harmonys.  Anyway, to get a workable tone I pulled out my old Boss Metal Zone, and after realizing I'm not really a metal head, (and the batteries on my practice walkman dying out) I started playing with the Metal Zone, and while I'm not a huge fan of the distortion sound, I was really digging the tone controls - it made the pedal a lot more versatile than it might otherwise be.  So I went hunting for the schematic, interested in the idea of splicing the tone controls (particularly the whole mid boost/cut and mid frequency knob idea) onto a distortion circuit I'm more into.  

I found a couple links on the schematics page here, and downloaded the two part .jpg set, and the .zip file, and compared the two and tried to figure things out.  

So if you download the .zip file - ( http://www.mif.pg.gda.pl/homepages/tom/files/MT2.zip ) and open it up, and look at the "mezon2.gif" file - that seems to be the tone control bits, right?  

So a few questions -

I assume the sort of sideways slashes (like coming out of the 2k2 resistors) are connections to ground?

That file has "1/2v+" connections - the other file (the two part .jpg one) has "4.5v" connections - I'm assuming the later is correct, and the first just means 1/2 of the voltage, not a half volt? And this voltage really just depends on the op-amps I use in the tone controls anyway, right?  

Looking a the "mezon2.gif" file inside of the .zip file again, if I wanted to try splicing this into another distortion circuit, I would do that towards the end of the circuit, and the signal would come "in" the point labelled "B" and "out" the point labelled "C"?  

Changing it up a bit, is this a good place to use some of those quad op-amps I have lying around, even though the original used duals?  

I think that's all I have to ask right now - I've never really hacked at anything quite this much before - I was thinking for now I'd try sticking this on the end of a dist+ type circuit, since that tends to be my favorite distortion lately, and I often find myself heavily EQing it when I run it into the computer, fooling around with mids and such, so I was thinking this sort of EQ might be fun.  Or it might not work at all.  I guess I'll see.   Any general pointers people have would be nice.