Hi Mike -
It should be possible, how handy are you with a soldering iron? The LANC controllers seem to be the same, it's just the interface and on the "D" jack, a signal that tells the camera to expect LANC data.

Other option, pick up the "old style" VCT-xxxxRM tripod or maybe just the handle, for instance I have a VCT-D480RM here, and I'd swap the handles if you've already got the one with the "D" plug and the threading is compatible... I think it should be, PM me if you're interested in that possibility.

Dave