Re: Faux files
You have a factory-finished masonite product; one well-known brand was Abitibi Board. The enamel was extremely durable and waterproof. Maybe consider just repainting with oil enamel (or an emulsion paint like Ben Moore "Advance" line)
Other than that, to eliminate the texture it would be better to go over with a wallpaper (after cleaning, sanding and priming so the paste can stick) such as a heavy textured/patterned paper like Anaglypta (or Supaglypta) or maybe a grass cloth or just smooth "liner paper".
Remove not the ancient landmark, which your fathers have set.