Uniden's bandplan info probably wouldn't work on the GRE/RS scanners.
However, presuming it's
this system and presuming they're now using the freqs listed in "Site 101", you should certainly be able to enter a custom trunking table to handle that system on a PSR-500-family scanner...
Starting with the "Rebanded" bandplan (since that system/site has some "rebanded frequencies" listed), you'd insert a few entries before all others. For any frequency between 851.012500MHz and 865.987500MHz which ends in "500Hz", you'd insert a table entry of the form:
Base: the voice frequency
Step: 25.000kHz
Offset: 759 - [(voice frequency - 851.0125MHz) / 25.000kHz]
Lo Chan: same as Offset
Hi Chan: same as Offset
For example, looking at that system, I see 854.162500 MHz. That's within the range above, so we'd insert a table entry:
Base: 854.162500 MHz
Step: 25.000 kHz
Offset: 633
Lo Chan: 633
Hi Chan: 633