Selling a very lightly used (2 forks, 1 frame, some practice) Smith WD 101 gas saver. These are very nice in that they give you a convenient place to hang the torch and can relight it instantly without having to readjust settings. I’m switching to propane (and TIG.)
BTW you can use it with propane too, I do with mine. The only thing you need to change is the pilot light doodad, a one minute job to switch. I can look up the part number if you can’t find it.
Mine was made in the '70s, used to belong to Mario Confente in fact! But the design hasn’t changed and all replacement parts still fit.
That’s my “newer” one. I have another, a Harris that’s way older but still works perfectly. Dunno how old but I found it in a 1920s catalog, looks identical to mine so it could be 100 years old.
One use case for a Gasaver is brazing with two torches to begin with, typically one of them a rosebud for getting the part up to brazing temperature quickly. Then hang up the rosebud on the gasaver so you have a free hand for holding the brazing rod. Also great for when you’re doing lots of little brazes, like braze-ons; saves the time you spend on lighting and adjusting the flame over and over. Nice ‘quality of life’ improvement even if you’re not too consumed with increasing production efficiency.