The codesets are the same, but the codes relate more to the positions of the buttons on the remote than they relate to the names of the functions. If the third button from the left is DVD on one unit and BAZOOKA on another, they will be the same code because they are the same button, but will do different things on the two different receivers.

The extended codes are good for discrete surround commands, but again, the function on one receiver may not be the same as the function on another receiver. Or, as Lyndel points out, some functions are not available. If you can't find the exact model number, try something with LOTS of buttons such as the RX-V9 or RX-V1, then test the commands to see what they do with your unit and rename them if necessary.