[sdiy] Wurlitzer 4420 service manual?

[gordonjcp at gjcp.net]

Anyone got any service information or experience with these old beasts?  Mine has a G ringing constantly.  I've had a quick look online and it looks like each key has a filter that shapes the pulse going to the reed, which I suspect may be the problem - possibly a resistor gone high?

>From what I've found so far the key click filter comprises a bunch of capacitors and 4M7 resistors for each key and stop, but I don't want to just wade in without some sort of diagram unless I have to.

-- 
Gordonjcp MM0YEQ