Try a call to PPL Motorhomes 800-755-4775 since they claim to know what replaces what. Have your Upper and Lower Model Numbers. PPL's "sale" price on new Uppers (Brisk Air) starts around $500. Penguin is more, but they might be able to tell you if a Brisk will work on a Penguin Lower... and what about the controls.
Maybe some OP will offer to meet you and to a swap-out once you figure the parts out. I've done some of that in my travels and it's been fun. Plus I've met folk in person I'd only seen in writing before. Never been disappointed!
