Check Engine Light / Codes from diagnostic

Great site!

I recently purchased a '98 ML320 and the check engine light came on. Took the vehicle to my BMW/Merc/Volvo mechanic that I have used for the passed 13 years for my BMWs.

Was told the codes were:

PO 442 - EVAP, LEAK
PO 460 - FUEL LEVEL SENSOR

Translation, "You need a new fuel pump"

I wanted to run this by the folks on this forum to confirm whether this is the case. The mechanic reset the system and the check engine light went off, yet it returned after a only been off for a couple of hours.

The vehicle seems to drive fine. There's no sluggishness nor other signs of poor performance.

So my questions are:

Was I given a correct diagnosis?
If it is the fuel pump, recommendations on the best place to purchase a new one? As I was quoted $515 just for the part.
Finally, how do I go about getting the maint. history of the vehicle?

Thanks!