Just measured my pin lock corny and it sits at about 22 1/2" or so... add the hoses and I think you'd want about 25" or so for total clearance space. Looking at the photo that bottom shelf/crisper area looks like its about the size of a gallon of milk... thats about 10" (yes I just bolted over to my refrigerator with tape measure in hand to size up a gallon of milk..) so figuring that its 33" high on the exterior... guessing that the actual space inside is about 4" shorter than that thanks to the insulating area you're left with about 19" of space... which is too small for a keg.
However, that crisper compartment looks like its totally removable.. just a piece of clear plastic so no worries there. Even better is that, judging by the photos, it seems like the coolant lines run in the back of the fridge which is a huge bonus. Most mini fridges seem to have a single coolant coil that runs into their "freezer compartment" only and obviously your kegs aren't going to fit with that freezer for your Hot Pockets in the way. Typically in a situation where the coolant line is only running to the freezer compartment you have to forcefully bend the freezer area down towards the back of the freezer thus risking creating kinks/cracking the coolant tube and ruining your fridge.
So the advantage here (if my assumptions from the photo are correct) is that you wont have to worry about any of this. The freezer and crisper should be easily removable without any concern for damaging the fridge.
So assuming everything that I said above is correct, the only thing left to be concerned with is whether or not all those compartments on the door would get in the way. Again though, there surely aren't any coolant lines running into this so its no big deal to remove it and cover it up the hole with some sheets of styro-foam insulation. All of that would add a little extra work but nothing too serious. Plus, judging by the dimensions given on the Craigslist add it sounds like you might actually have a chance of fitting 2 cornies in it if all that door junk was stripped out! Bonus!
So the short version of my answer is:
Contact the seller. Go give it a look and see what you think. Take an empty keg with you to help you size it up. If it looks like it will work, take $50 out of your pocket and offer it to them... If they decline pull out the extra $25. With Craigslist its always worth a try to save yourself a couple bucks! I recently bought a chest freezer for $75 that the seller was asking $100 for.
On a couple side notes:
1.) Hello fellow Seattleite!
2.) Act fast on Craigslist! It took me a month of religiously checking ~10 times a day before I found a freezer I wanted that was within my price range before I finally found one that hadn't already been sold!
3.) I'm gonna risk sounding like a creepy internet stalker person here and assume that you understand that I just want to help out a fellow Home Brewer and say...If you don't have your kegs yet and wanna go size this thing up I just got my kegs last week and I'd be more than happy to roll with you to check this thing out, keg in hand. I'm free all day tomorrow so PM me if interested and we'll sort out a way to meet up.
4.) Check out my Keezer build which is now in progress
5.) If I've got some free time I'd be more than happy to help you with your build... just don't let me cut any wood...you'll understand why after checking out that link to my project.