Apparently I’m going to have a 2lb chunk of Wisconsin’s finest delivered in a few weeks. Trouble is, is that I don’t think it’s going to be very fresh. The store claims to have had it hanging around (or “aging” as they would have me believe) since 1997. 1997? Did I hear correctly? What should I do with this festering sock-like substance when it arrives? Grate it onto frozen pizza? Find some fancy crackers? Let it run free in the back yard? All and any advice welcome 
Well, I’m not a cheese doctor, but maybe I can pitch in.
Two years ago, I got a handmade gift basket from my folks from Christmas. My father had huge wheels of cheese delivered from Tennessee, and for months, he aged them in the back room, turning them every Sunday. It was the most delicious cheese I’ve ever had.
You do not have a lump of mold. You have what many consider a delicacy. Break out the wine, throw on some jazz music, light some candles, and enjoy. (Excuse me while I wipe up my drool.)
Wow. That there is some expensive cheddar. You must let us know how it is. I get 8 year old Wisconsin cheddar fairly regularly, and I think it’s around $8/pound. Then again, the stuff I get never won any awards. Now I’m intrigued.
It’ll be a bit chalky - not smooth like fresh cheddar - and strong. I’d suggest serving it on fairly bland crackers, like water crackers, so the taste isn’t diluted. Wisconsin cheddar also goes well with a good salami or smoked fish, if you can get it in the God-forsaken part of the world where you live. 
Have it with a good microbrew. A stout, or a really good IPA. Something about a really hoppy beer and aged cheddar makes me go “Mmmmmm”. Of course, it’d probably go well with a really rich red wine, too. An aged Bordeaux or Burgundy. Nothing too fruity.
You could probably make a kick-ass macaroni and cheese with it, too, but I’m guessing you don’t want to dilute it such.
Cheese that aged should be treated with respect! They are overcharging a mite for it, but hey, whatever the market will bear. I have paid up to $24 a pound for a decent 9 year old cheddar.
Otherwise, Athena gives good advice. I like the aged cheeses best on rice crackers; they have a lovely texture, and the simple flavor enhances the sharp cheddar.
Or some crumbled or thinly sliced on an english muffin, with a little butter and onion, or onion powder.
or grated in a cheese omelet.
The flavor will be strong, the texture granular, and there will be some calcifications in the cheese. To me, this all enhances the experience!
I think maybe I should have added some ;)s in the OP.
Now, should I open a bottle of wine with my cheese? Port perhaps? Or maybe stray left field and try a nice fruity Gewurtztraminer from the Alcase?
Port is nice with cheese. A favorite is Port, Stilton and almonds together.