Yes, well that's the short answer. The gauge threads into the fitting, so you can get a new gauge with an 1/8 inch bach thread and a little teflon tape and thread a new one right in.
http://www.aquariumwaterfilters.com/Pressure-Gauge-p.pg-aee.htm
We do build our systems in Winter Park, Florida. So we have all the parts.
Feel free to give us a call 407-599-2123