M20c Fuel pressure gauge issue

[Janat83]

My fuel pressure gauge shows wrong readout, when starting the engine with fuel pump on it only moves a little bit, then during flight it was stuck at max limit, when I landed I put the fuel selector on off and the engine shut down while it was still showing Max as in the picture. 

1968 M20c

Part no. 660012-001

If that part needs to be replaced where I can get it from? 

[Andy95W]

Mine has started doing that, too, but very intermittently. I expect it to get worse over time so I'm planning on pulling it out and send for overhaul.  Price seems to be about $350-500.  The fuel pressure line probably needs cleaned out with mineral spirits also. 

Hopefully someone around here can provide suggestions for a good instrument overhaul shop, otherwise Trade-a-plane usually has a bunch of advertisements.