Surprisingly, the Moon is not as accurately mapped (particularly with altimetry data) as Mars.
LRO instrumentation is not related to Mars Express. MEX was actually loaded with left-over European-built instruments from the failed Soviet Mars-96 mission. Most of the high quality Mars mapping data is from the Mars Global Surveyer, which orbited for ten years and had a laser altimeter. LRO is closely related to the Mars Recon. Orbiter that is currently circling that planet.