My kitchen tambours were missing. The PO replaced with cheap paneling sliding in the grooves and that was falling apart.
I replaced with 1/2" birch and stained. I am NO woodshop guy at all so you can probably do a much better job than mine.
You can see a picture at my website. The before picture is terrible, since I did not know it was going to be a before picture when I took it
The rest of the bottom tambours were broken or missing and I have not done anything there other the get rubbermaid bins that fit those locations.
Luckily the top tambours seem to work after some silocone spray.
The bathroom tambour works very poorly. But there does not seem to be a better solution since we shower in there.