I'm surprised that the Samsung doesn't have some sort of audio output - that's kind of annoying.
I went hunting for info on both the TV and the DVD receiver. Sure enough, there's no mention of audio output on the Samsung - I guess when they yanked the OTA HD tuner out, they pulled the audio output entirely. The Onkyo manual took forever to download, but it finally did and I got a simple answer to a potentially difficult question that I had. I wondered if the Onkyo would transcode composite or s-video inputs to the component video output. Lo and behold, there are
no video inputs, thus there is
no transcoding.
I'd run component video from the Onkyo to the TV, then run stereo analog from the VCR to the "Line/TV" input of the Onkyo and composite video from the VCR to the TV.