Craigslist Beverage Air Kegerator - should I go for it?

I've been watching craiglist for a while for a beverage air and I saw one recently that potentially could fit the bill.

I'm set up to see (and potentially buy) this Kegerator on Sunday - they were asking $350 but she said she would take $300.

My concern is this thing looks old (maybe the one before BM23?). I told the woman to have it plugged in and cold to look at on Sunday. What else should I look for when I check it out? (from poking around looks like I should check for rust in the seems inside etc). I'm guessing if I find anything of issue I could probably negotiate the price.

Her description is "This kegerator is in great shape and comes with a full CO2 tank. The lock is broken, but the door stays shut and can be opened/closed with a screwdriver."

The lock doesn't concern me - really concerned with it's ability to keep beer cold primarily.

I'm normally a lurker here but signed up since it's a big purchase - any help would be really appreciated - thanks!

Here are the pictures;