Seal between Cab and box

Hey guys. I'm new to this forum and new to RV'ing. I recently purchased a 1999 Fleetwood Tioga with significant water damage to the cabover section. I'm a handyman and have decided to do a major renovation on it. I have removed the the bottom steel frame and the divider walls because the frame was rusted through and the walls were literally completely rotted away on the bottom and sides. Anyway, when I removed the walls and steel frame, there was a foam gasket between the cab and the walls. It is a neoprene type gasket with double sided tape on one side so it would stick to the cab. In retrospect, I wish I had been more careful to salvage it. It is a white foam tape, about 1" wide, 1/4" thick (original thickness). I have asked Fleetwood for information, but the original manufacturer is no longer in business, so they don't know. Does anyone have any idea what this stuff is and where I can buy it?

Thanks!