embossing text on curved surface

I have a segment of an ellipse.  I want to put text on it so the text will be cut to the same depth no matter where on the curve it appears.  I have been unable to find something that wraps text on a general pattern, just on a cylinder, which is not sufficient.  Is there any support for this, or is there any reasonable workaround?  The curve is quite gentle, and my current thought is to put the text on a flat plane on the flat back of the object, and then project upwards to the surface, and place the letters on sketches that are tangent to the surface using 'use' then cut them to  a fixed depth.  The error across the entire letter will be too small to notice from fifty feet away.  The lack of a "plane tangent to curve at point" makes this hard.

Here's a link to a prototype of what I am trying to do; the dimensions of the objects are the same as the dimensions in the intended (one-only) product.  You might assume something like using a CNC machine using a 1/2" square end mill routing bit or a 3/4" V-bit.  The shape you see is carved by that machine out of a solid piece of material.  The 1/2" square cut will probably be visually less sensitive to slight errors induced by cutting relative to a flat plane (one plane per letter).