Going back to the original question.
As JR mentioned, SMPTE/EBU code on track 24, slave the JH24 with synchroniser from workstation. Workstation should be master. Downside of this whole setup is the time wasted; since you have a "code only" master, the slave will not know where it is until you play the master, and will now be in the wrong place and will chase back. You could output master code all the time, I suppose. Some sychronisers had the option to chase to stationary code and wait for it to start rolling and put the slave into play. (Because the master is not outputting transport tallies to the synchroniser).
I've used Fostex 4030 synchroniser quite happily, but you need a pro to do the hookup. Also, with the MCI there is no synchroniser port, so it might be easier to put one on. (As opposed to digging into the Jones/Beau connectors). I've done it using S29 transport convention from SSL so it's a extra 25D connector and a switch to steer the synchroniser's 19K2 capstan control into the transport.
The Zeta3 works well, but the best chase routines were the Lynx Timeline.
It all seems a bit of a pfaff, though. A studio I did recently just ran the live tracking through the 24-track straight onto PTools, so the tape "sound" was on PTools immediately. I appreciate that odubs become an adventure at this point.