It looks to me like a device made in very small numbers*, out of Delrin rod or similar, so it should be fairly easy to make something similar (or even very similar if you need interchangeability). Or it could be anodised aluminium, and apart from the anodising just as easy to copy. If only we knew what went on inside it. It can't be just a handle, or the wire/pipe going in one end would come out the same colour …
* I expect that the demand for oxalic acid vaporisers is fairly small, after all.
Regards, Tim