yes, I did same, use the zip ties to holding the new flaps, even I install stronger metal support, just want double secure it.
I think I bought them from Amazon, the size little bit bigger, I cut them to fit, was very easy to cut.
You might want add stronger support for the flaps, You can buy the 2" metal bar from home depot and mount to the frame to support the flaps. I did it, so far so good.
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