Here you go.I'm for fuel pressure but couldn't find any for 50 to 60 psi. Most were for carbs and tbi pressure
Tinted 7 Color 100 PSI Fuel Pressure Gauge
GlowShift’s Tinted 7 Color Series 100 PSI Fuel Pressure Gauge Allows You to Ensure that Your Fuel Pressure is Running at Optimal Levels and is Not Too Low.
www.glowshiftdirect.com