Hi, look at the sills make sure they are ok, open lower tailgate and look at the bottom for rust but most are ok. Also check rear wheel arches inner wings and inside rear load space should be dry , i have seen some that have been wet on the back seats smell for foist as the weather has been dry for a few weeks. Check the cooling take for a run if you can and find a good hill and watch the temp , i have found that the radiators block up also check viscus fan. Put the heater fan on see if it works as they are a pain to change, make sure you get 2 keys with it as i think you can only have four in total if you loose one, should have key number on back.
You should get about 27 mpg round town maybe 35 / 37 on a run at 56 mph, but i have found they are a bit slower than my disco was, nice to drive !!
Good luck and have fun
Regards Colin..