Peter,
The wrist band is an assembly, and can be ordered by a dealer. Note: most dealers will not stock this item and will have to be ordered from Mares. Part # listed below is for the straps only, not including the pins. I assume should you replace the straps, you will already have the pins.
44200690WRIST STRAP KIT
In theory the console for multi gauge config can be ordered, however you would need to order the console, and pressure gauge to make it work.. Part numbers listed below.
44200634BOOT FOR CONSOLE 2 gauge computer / pressure gauge
44200635BOOT CONSOLE Mission 3.. pressure gauge, computer, compass
Hope this helps you out.
Best,