Paul, even if a ready-made housing can't be found, it's a pretty simple job to either drill and tap a hole in an original housing, or silver solder or braze a pipe fitting onto the top of one. I've done that at times when I needed another pipe thread for a fan switch or temp gage.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!