Snagged a new (used) Silver C

So I grabbed this Genesis off Craigslist for $150 - not a bad deal (?) It's in great shape overall but I've already thrown out the rusted grill grates and flavorizer bars, with replacements ordered and coming in the mail.

My side burner knob is entirely stuck, however. The previous owner said they never used it. I can't turn it with the handle, and I can't turn it even with pliers, even if I press it down. Anyone had this problem before? Should I just call Weber CS? Any advice welcome. Thanks!

I would call Weber CS. They will definitely help you and most likely for no charge.
I had a Silver C for 8 years - it's a great grill.

It ended up being nothing a little WD-40 and elbow grease couldn't handle