Its a Jeep.... you probably have to buy half the dash
But seriously its a single assembly so the whole cluster. Also i'm unsure where the odometer information is stored so there may be security issues if you just swap it over with another one.
Of course I'm just guessing, as you said its rare so no information out there.
Of course it could just be a dry joint... so if you have a mate that electronically inclined an inspection / rework MIGHT be effective - but apart form that you likely on your own.
Wouldn't hurt to ring a Jeep Wrecker.... they MAY have some experience with this sort of "swapzies" thing.