Rich,
Sounds like you know all about these summit grills. This one isn’t hopeless, I suppose, but you could rack up a fair amount getting it up to 100%. The entry price was certainly right
!
The first thing I would look hard at is the front of the firebox. Is there rust or worse yet holes in the steel part that surrounds where the burners go in? If it is bad - a very good probability - I would recommend considering this a parts grill. If somehow the front is in good shape then take it slow and steady. I personally have learned through bad experience to despise this latest generation Summit, but others really like them. I would rather have two classic Genesis grills or if you really want a Summit search until you find the previous generation in the Platinum version with all stainless frame and stainless lower cart. The cheap metal Weber used on the Summit you picked up -as demonstrated by the condition of the cart - is inexcusable for a high priced grill.