Part 2.
Auxiliary and middle lines.

1 Remove the blocked pattern below the letter.
2 Draw tangent circles and a line through their centers as in figure "II_1". Delete the circles.
3 Select the inner curve and use the "Offset" command to draw a new curve through the point as in figure "II_2".
4 Cut it and connect the remaining short part to the outer curve.
___II_2_2___
5 Draw circles tangent to the inner and outer curves starting from the upper end of the "C".
___II_2_3___
6 Use the "Freeform / Through points" command to draw a center line through the centers of these circles. Remove the circles.
___II_2_4___
7 Trim and remove the unnecessary from the intersection of the center lines.
___II_2_5___
8 Extend the segment to the inner curve as in figure "II_3".
9 The construction of the middle and auxiliary lines is finished.

https://disk.yandex.ru/d/5pk5oYZwTwerNg

To be continued ...

Hi Gunter,
Here is the text, modeled with the extrusion angle you pointed out in your last file.

I used the centerline from the original file I posted that i got by converting a Vcarve toolpath into geometry. I flattened it and then set it at the depth of the tool you posted. Then just hand modeled the sidewalls to simulate an extrusion...They are solids. But they won't help you in Vectric..




Anyway........

Part 3.
Final.

Frame.

1 Select the center lines and from the front or right view move them to the desired distance.

2 From the '3D' view, use the 'Lines/Line' command to draw lines as in figure "III_1".

Surfaces.

1 Select the triangles and apply the "Planar" command to them
2 Select 4 lines as in the "III_4" image and apply the "Network" command to them.
3 Using the "Sweep" command build a surface like in the image "III_5".
4 Select the 2 surfaces, image "III_6", and apply the command "Boolean/Merge" to them.
5 Remove the unnecessary parts.
6 Build the remaining surfaces with the command "Network" as in image "III_7, III_7_2".
7 Combine the constructed surfaces with the "Boolean/Union" command.
8 Unblock the oval and apply the "Plamar" command to it.
9 Select the resulting surface and apply the "Boolean/Diff" command, select the constructed surfaces and complete the command.
10 Hide the plane of the oval.
11 Select the oval and apply the "Extrude" command to the desired height.
12 Remove the top part.
13 Return the hidden part and use the "Boolean/Union" command to merge the desired surfaces.

https://disk.yandex.ru/d/9I0HXeZKOr5h9w

This is only one of the options, and not the best, try and feel free to experiment.

That's all.