My recommendation is to get an old hp measuring device that is broken, unpopular, or about to be thrown away.
The hp enclosures of the time were solidly constructed frames covered with diecast aluminum frames.
A little sheet metal work would make a very good enclosure.
However, sometimes (e.g., models with low selling prices) a cheap sheet metal frame that is not a diecast frame is used (later models of the hp 3478A). Careful selection is necessary.