Well if you can find one, there is a product called Fuel+.
It's a fuel management system that replaces the clock display.
The original version was designed for the clock, the newer version, that's also not available new anymore, has a separate remote display.
Check on the ibmwr sale pages as they show up there sometimes. More often than not you will find someone that may want to trade the fuel+ for a clock display in exchange.
If nothing else you could post a wanted add for one.
You could also post for a replacement clock assy as well.