The plastic stove vent flapper on my 2004 Fleetwood Prowler 24BH TT has been torn off. I have searched the internet high and low for a similar vent with no luck. All that I can find are roof vents, or replacement stove vents that are rectangular. Mine has a semi oval top shade rather than squared off rectangular. the shade is fine, just need the flapper valve but i assume I will need to replace the entire thing. Does anyone know where to get one of these?