JVC HM-DH40000U already provides a line TBC and frame sync, but doesn't remove copy protection:
http://www.digitalfaq.com/forum/news...html#post41893
The VCR's internal TBC can't be disabled, which means adding in the TBC-1000 provides no benefit unless you want to capture Macrovision tapes. And I would argue if you want to do that, it makes more sense to use a capture card that ignores Macrovision rather than a $$$$ TBC box.
Adding a Panasonic DVD recorder or any other device to attempt external line TBC is completely useless, because the line sync information has already been stripped from the signal and re-generated.