[HAM] Hum in c-3/leslie 147

[figjams at comcast.net]

Hi list

I am looking for experienced troubleshooting here. 

My C-3 #67135 and 147 leslie has a hum when keys are contacted(played) 
I noticed it months ago but seems to be getting worse.

Also seem to hear "leakage", based on others description of such an event.

Am lookiing for some low cost solutions to try before getting into cap or preamp rebuild, etc .

thanks in advance
if you want off list, send me email

figjams