Help with a Cornwell CGTDTI001A Inflator

[Jbullfrog]

I got this in a box of stuff and it looks like it had a gauge. I extracted the broken plastic from the fitting on the front. any idea on the thread or where I can get a gauge. I'm guessing Cornwell will say they don't service it anymore. I tried searching online and can't find anything.

 

[Zewnten]

I'd put money on your guessing correct with cornwell. I'm blind though what part are you replacing?