E29 Engine Instrument Gauges

I have a panel of three engine gauges on my E29. The water temp gauge is shot and a new wire to the sending unit did not fix the problem. I tried to remove the single gauge as they are pretty inexpensive and simple to replace. But low and behold, I cant get the old one off, even after removing the backing bracket screws and using all my might and a big set of pliers.
So is there some trick to getting the gauge out--or am I destined to replace the entire panel? I've enclosed a couple of pics to help illustrate the situation. Any help would be appreciated--before I decide to replace the entire panel with new gauges and switches.

Gary
1977 E29 "HydroPhilic" Hull #515
Rogers, AR

Once you've removed that angled piece of metal that squeezes the gauge against the faceplate, I don't think there's any magic associated with how it's mechanically held in there. It might have a rubber gasket that's turned to goo and made things sticky.

If the gauge is broken, it's worthless, so my escalation would be (once I had a replacement in hand -- see moyermarine.com if it's an Atomic Four):

• tapping the back of the gauge with a rubber mallet
• turning the gauge with a big pipe wrench
• cutting the #(*&(*@ off with a Sawzall