Vintage Synth Repair

Hello Everyone,
 i just bought a Moog Opus 3 from someone for $400, which is a hella
deal considereing its near mint with slight issues.  Ne ways i powered
it up and played it for a about a day on it and then the filter board
when out.   
        Can anyone specify what parts i should buy to replace the
filter section.  im thinking of getting the parts from VINTAGE
PLANET.com  but i not sure exactly what i need. 
       IM also trying to bring back to life a Korg Delta, Roland VK-09
and Roland Juno 106 if anyone has any ideas.