I have the 1Z0035729B fitted in my pre FL Scout - Can I simply swap this for the newer 1Z0035729D model without needing any recoding etc?

Not exactly.

Yes you can swap out the interface - It's a straight swap however the interface does have some coding of it's own. I would think it'll still work ok but get it tidied up when you next get a chance.

Why do you want a 729D?

Been playing and trying to get full phone functionality back after the firmware upgrade...

My phone unit is 1Z0035729 - without a letter suffix! :confused:

After the firmware update the long coding for the RNS 510 had reset to all zeros, this has now been put back to what it was before the update, so no errors are now showing.

My phone (TYTN II) is still not fully recognised, however, when paired with an iPhone all is OK :confused:

Having got used to the 6 shortcut options, and the easy way of search the address book via the Columbus, and don't really want to go back to scrolling via maxidot.

So thinking about buying a new unit/kit, swapping the control boxes and then sell on the other.