The 2009 manometer is 1/8npt with a direct fit to the gauge block in the tube. The gauge design was changed back in 2019 to all guns even the p-rods which shared the same setup. Manometers are now converted to 1/8bsp. It’s best to order the gauge from Crosman customer service because you will get a new gauge plus the matching gauge block with it.
Knowing the gun has some age to it , it might be best just to re-seal the entire gun anyway.
If you want to take a chance on just the gauge only you can find them at McMaster Carr.
The gauge was changed for ease of sealing and less leaking during factory testing.
