Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4618831.
Voigtlander Vitessa is a very cool camera, the original hood was the 125/20 which is a push-on external hood. Those are hard to find and expensive.
My Vitessa N with Color Skopar 3.5 has a OD of 34.5mm and ID of 33.0mm. This dimensions have also been confirmed for the Ultron 2.0 lens in the Vitessa A series and the Skopar 2.8 in the latest series.
This is a remix of https://www.thingiverse.com/thing:1168491/ and https://www.thingiverse.com/thing:39683
R1 has 2 versions, one for mounting outside the lens (external) and one to mount inside the lens (internal)
R2 is a modification of the previous, only for external mout, with thicker wall and larger rectangular hood plus a hole for a cord/lanyard so you don't lose it.
I printed these in PLA, adjust your scale for shrinking is using a different filament.