Hey 
 
I'm pretty new to the world of organs, and totally new to this forum.  I really have no idea how to play an organ.  My grandmother passed away last year and I now have the organ, which is a Hammond Regent 4172.  Everything works on it as far as I know, but it hisses like crazy; probably oxidized contacts on the board connectors. 
 
I want to MIDIfy this thing.  All I see are complaints about how awful this organ is, but I've always liked it since I was a child.  It's not a requirement to keep the original sound working, but that would be a bonus.  So I've been looking around at different methods to accomplish this, and so far MIDIbox seems like the cheapest and easiest way to go about hooking everything up.  I don't have the organ at hand (just a picture) so I'm probably not going to buy any parts until I get home in a couple of months.  I would like to know if the manuals are matrix wired or individual (same for the pedals and stop tabs.)  There are a few features I have no idea how to add, like the percussion section, and that weird slider thing between the manuals.  It also has a built in leslie, which is controlled by one of the stop tabs I believe. 
 
I wonder if I could also use MIDI to control the original electronics for recorded playback. 
Here's what I can make out from my picture; I figure I can use LEDs to show the status of the stop tabs, regardless of which position they're in.  Motor/solenoid control on the tabs would be cool but I think that might be too difficult. 
 
Here's a picture of it, and following is a list of what I assume are all of the connections; 
 
 
 
49 tabs 
61 swell 
61 great 
25 pedal 
volume pedal 
5+1 piston radio buttons 
slider thing + toggle 
16 percussion radio buttons 
6 percussion toggles 
percussion on/off 
pistons led 
2 other toggles 
tempo pot 
2 other pots 
4 or 5 position rotary switch 
4 illuminated pushbuttons (A B C D) 
2 red and 1 amber led 
power switch, lights pushbutton 
 
This will be the first project like this I've ever attempted.  Soldering and electronics aren't a problem, but I've had little to no experience doing any kind of programming.  I kind of like the way the new STM32/Core32 looks, anyone used these yet?