that looks very similar but mine have the little hex head cap screws with wing nuts on the back. I am afraid that once I get them off how the heck do you get them back on after repair. There is not much room for your hand.
I went out tonight and I think I can get to the nut on the back of the gauge, I would think that would allow the gauge to pull out.
I also did an ohm check on my sender unit and it checked out at 240 ohms at 0 PSI so it should be ok per instructions
Thanks for posting pic and help also