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Schematic for Sherwood RX-4109B Receiver

I am trying to get a dead RX-4109B back to original operating condition. It is obvious that someone has worked on this unit previously (missing screws, excessive thermal paste, wrong transistors on the heat sink, etc.).
This effort has been frustrated by my inability to get a correct schematic for this unit. The schematics downloaded from this Web site are different than the unit I have. The mother board has the following numbers 7020-07421-030-05, top & bottom. The serial # of the receiver is: Serial No. RX - 4109B/V \V(A) 14.09015P1433. Any help or advice on getting a copy of the correct schematic would be greatly appreciated! Thanks, Len