All JVC VCRs that I have worked with have all seem to have the same IR codes, the exception being the newer digital recorders. I use Crestron, but these codes must also exist for other systems. VCRs that I can verify working w/ discrete on/off input selection include:

HRS-3900 HRS-3901 HRS-7800, HRS-9800, SR-TS1U

Note that if you use the IR jack on the back, you will need to strip the IR carrier frequency from the driver, or use a Xantech bridge.

Also note that the rear input selection was mislabelled on the JVC / Crestron driver that I was using. The driver I use lists the LINE1 discreet command as LINE2.