Need weatherstrip insert for interior door threshold

The weatherstrip insert for the threshold of one of our interior doors has failed, and I have been unable to find a replacement.

It was installed when we rebuilt our house in 2008.

I​'ve attached both a jpg​ of the cross section of the weatherstrip, and a sketch showing its dimensions.

If you have this style, I would like to buy some replacement weatherstrip.

If you do not sell this weatherstrip, I would really appreciate any help you can offer to identify a possible source.

Thanks for your help.

Ron