I have this range, and you are pretty clos on the date. I think we bought ours in 2014 maybe. Wolf was eliminating the open burner option from their line, and we got one of the last ones available.

I am by no means fastidious and am more on the laid back end of the cleaning spectrum, but I know my range doesn't look that bad under the burner pans. I'd try Krud Kutter for a start for the part under the burners to see if that helps. Are the burners themselves even functioning, or all of the holes blocker with crud?

The drip tray has lots of play, so I'd start by jiggling it side to side to see if it releases. Frankly, I can't imagine that there is that much stuff spilled in there that it's solidified in.

I've really liked the range, and I think after you get it cleaned up you'll be pleased with it.

Good luck.

Thanks so much @julieste! This helps a lot. i was really dismayed to find such a mess when I opened it up and got a better look inside. Fortunately all of the burners are functioning but I’m holding off on testing it further until I can get most of that grease out. I did as you suggested and tried jiggling the drip tray side to side (and every which way!) but no luck, that thing is stuck in there! Many thanks again - I’m really excited about this range!

Call Wolf customer service as your next move.

I would contact Wolf.