purchased a used mst xxx-d

So yesterday I got into a bidding war on ebay and won a mst xxxd lot.  Spent more than I wanted but then again not really as I bought 15 rc cars this month haha.
So this is what I got in the roller is a castle 5400kv motor which I'll use in something. Uknown servo.  I think a spectrum sr210 which might be compatible with one of my remotes. NIB speed passion reventon 1.1 pro and 17.5t motor.  Hpi tires,  mst wheels.  A car stand.  A turnigy battery. new magnetic body post kit. And what looks like a cheap body.  
Seller claims he ran it once, Then bought electronics to upgrade. I dont know if I belive it completely but not all that worrried about it.
So main question is what upgrades do you all recommend for the xxx-d?
Here are the pics