When we had our operation, I used these as a young man. They always performed well! The one Marquette gas analyzer is missing the piece that goes into the exhaust, chances of finding that is probably null. That timing light is one tough unit, and still works great!I saw a almost complete small gauge testing kit at the Turlock swap meet and forgot to grab it. IT had a gun just the one in the first pic.
Mike
About any brand will work, Sun, Bear, Allen, etc as long as the tubing size matches up. Now if you want an original one for restoration, that is another matter.The one Marquette gas analyzer is missing the piece that goes into the exhaust, chances of finding that is probably null.