Unfortunately, as a rule it's a lot harder to rip 3D model data from a PlayStation game than it is to rip textures (and sounds, etc.). The reason for this has a lot to do with the PlayStation hardware itself.
Essentially, the PlayStation is able to draw textured polygons on the screen wherever it's told to via the hardware itself. The reason for this is that it's easier to make a chip that does one specific thing quickly than it is to make a chip that does anything quickly. It also means that game programmers don't have to tell the system how to draw polygons, as it already knows how.
That's also why texture maps on PlayStation get "blocky" when they're stretched, while textures on the Nintendo 64 get "blurry" instead -- the systems do their hardware drawing differently, and for all practical purposes there's no way to tell the hardware to do it differently.
What does this mean for ripping assets from Klonoa? Well, the PlayStation knows how to draw textured polygons, but the game itself needs to place the textures in a specific chunk of memory (VRAM) and in a specific format in order for the hardware to draw them. Thus, if you want to rip a texture map, you can always find it in the VRAM while it's being drawn.
Why doesn't this work for 3D models as well? (note that I'm not an expert on the PlayStation's architecture, so there might be some inaccuracies here) It turns out that the PlayStation only really knows how to draw two dimensional polygons. This seems crazy, but remember that 3D wireframe graphics came long before fully-textured 3D graphics, because it turns out that the "3D" part is actually a lot simpler to do than the "textured polygons" part. That means it's up to the game code itself to do the 3D projection math that determines exactly where the polygon goes on the screen (since it ultimately becomes 2D on the screen anyway).
Since the game code itself is doing the 3D projection math, this means that different games have the option of doing this math differently from each other. Consequently, they also get to store the models themselves in any format they want. There are some known formats that are used in multiple games, and there are lots of tools made for ripping models from specific games, but nothing that works on all games. To my knowledge Klonoa hasn't been extensively reverse-engineered, so I'm not certain whether it stores its models in any "known" format.
In theory it's always possible to start from when a game draws a polygon and "step back" to figure out exactly how it decided to draw that polygon, but this can be very difficult and time consuming. The math needs to take into account a bunch of different things, including position, rotation, and scale of both the models and the camera, in order to figure out what to draw where.
It is of course entirely possible that the .tmd files you've extracted are the models in a known format, but unfortunately it's also possible that Klonoa's version of the format might be slightly (or extremely) different from formats used in other games. I'm going to do a bit of digging to see if I find any useful information.
Also Hi, I'm new.