Jeep FC170-1958
Pop off the needle, same on the old and new gauge
The new gauge will require removal of the screws
Old gauge, will require drilling of the brass revits
The mounting holes are spaced different on the new speedo, overlay the old one and drill out the tin old gauge face
Install the needle back on the face and install the screws. Unfortunately the old needle will not work and the odometer isn't perfect. Fortunately I don't give a shit
The old faces for the water and fuel gauge are opposite so they won't switch over.
Install the temp / fuel gauge back into the shell
Assemble the same way it came apart
New guts, old look