If you want, I can:
Since ArtCAM is discontinued, users should migrate to:
Recommendation: For long-term access to ArtCAM files, acquire Carveco Maker+ or Carveco (successor product). It includes a built-in ArtCAM file converter.
DeskProto is a multi-axis CNC programming software that prides itself on reading "orphaned" formats.
Once you have a converter, which format should you choose?
Pro tip: Always save two copies after conversion. Save the STL for machining, and save a high-resolution PNG depth map of the relief. You can re-import the PNG into almost any CAM software (like Vectric's "Create from Image") as a backup.
Relief files often include color-to-height mapping data. This visual data may not translate perfectly to monochrome STL files without texture mapping support.
Carveco was created by the original developers of ArtCAM after Autodesk shut the project down. Consequently, Carveco has the most native support for legacy .art files.