Hey Liondancer.
Perhaps my message is a bit late but I have the same vehicle and started work on it last week. (feb 2009)
Mine has been sitting around for 4 years with the occasional startup.
I went straight to the cooling system first. everything worked ok however I didn't want to take any chances. (just as well.....read on)
Took the radiator out and got it professionally cleaned, bought a new radiator cap to go with it.
Got a new thermostat from the local merc guys and gave the system a good flush with the garden hose.
Put it all back together and while I was at it, thought I may as well change the radiator and heater hoses.
No issue with the radiator hoses, just a precaution.
Took the heater hoses off and found both hoses had part of the metal pipe rusted through and broken off in side!!!. (even tho water was clearly running through).
Cut the pipes back a few mm and flanged the ends with a plumbers flanging tool. Put the new (marginally longer) heater hoses on and filled it up.
All seems to be working 110%!!
Have since found more heater hose sections (2) and am going to replace those also.
The water pump works fine however I was surprised how inexpensive a new original one is, so I propose to replace that also.
And I thought a home style radiator flush would do!! I consider myself lucky. A cooked engine wasn't far away.
Hope the info helps.