Hello! Unforunately I cannot share any of the 3D files due to license agreements!
That's okay, but can you adjust the camera by 33 degrees instead of 45 on the y or z-axis to get the 2:1 pixel ratio for isometric? Here is an example screenshot of what I mean: the tilesets you made are similar to the block on the left; the block on the right follows a 2:1 pixel ratio and is what you would call isometric, while the block on the left looks similar but it's not isometric it's dimetric because the top white space is a lot more visible and disproportional compared to the block on the right that is a little bit disproportional (because isometric isn't exactly 100% possible without 3D). Still, it looks close enough to all sides having more equal proportions than only two sides and one huge diagonal top.
It could be much work to manually edit the tilesets without losing quality. However, I am assuming you might still have the original 3D files, or you used something from 3D to render these tilesets, and it might be easier to just adjust the camera and re-export the images.
If it's too much trouble, I guess it's alright because you have reasons to use dimetric instead (it's more compatible with an orthogonal grid; in the example above, the dimetric block matches a straight grid perfectly, while isometric needs a particular type of tileset like the one in Godot or Tiled to skew the axis and half the y axis). Thank you for your response.