I have a 47 Chevy 2D on a 1988 Oldsmobile cutlass frame with SBS 305. Noticed oil leak under the dashboard. I see some oil sports on the steering column, driver side carpet and center of dashboard. its basically damaged the radio too.
But could not find where is it from? no evidence on the firewall or any cables?
Do you have a mechanical oil pressure gauge? I know this is an obvious question, but I've had leaks before where the line goes into the back of the gauge.
I go to Home Hardware and buy brass fittings from them. They sell the ferrule individually for under a dollar. Get a couple in case you drop one. You should be able to use the old compression nut. Like DJD said, make sure you have a nice clean section of copper tubing, don't over tighten but you definitely want a secure fit. Good luck, I'm glad you found the leak.