I like electric gauges for street cars. I don't like hot high pressure
oil inside the cockpit. I guess I'v had too many leaks over the years. No sense replacing what you already own and is (probably) working fine.
I would replace the sender with the correct one and see where that takes you.
In the mean time, go through the wiring and make sure it's all in good shape. Solid connections, no kinks or damage, etc. If it is, and the current gauge is working fine, move on!
Life is too short to worry about minutia.