4thstring, welcome to IRV2
Glad to have you aboard, if you take the control knobs off will the post turn with a pair of pliers? Not sure if you can lube post to see if it will free up to turn but you could give that a try. Have you ever used the oven?
If it will not free up a new control is your only choice. The RV-WIZARD will pick this up maybe he will have a answer for you.
If you would post coach info in your signature-profile block and that info will follow your every post.
Enjoy the forums.