Hubley Texas Junior

Hi everyone, im new to the site.
I found this beauty while detecting at my sisters house. I have tried to find this particular model on the internet with no luck.
It has Texas on one side and Junior on the other and looks to be a single cap round, not a chamber that can be removed and is very simple in design.
All the ones I could find on the net had Texas Jr on the one side and were multiple round caps and had alot of filigree design on them.
Can anyone help me out with what I have here, how old it is etc...

Thankyou in advance ??