no dash lights

Since all instrument lights are not working you need to check:
1)instrument panel fuse
2)connector at circuit board
3)circuit board for crack near connector
4)headlight switch connection

My 65 Dart Instrument Panel Wiring Diagram labels the wire connected to the headlight switch as E1 tan.

The same wire connects to the instrument panel fuse.

Wire E2 connects the fuse to the circuit board & it is orange.

Using an electrical testor you can check for voltage at each connector on each end of the wires & fuse......I would start at the fuse which is frequently effected by corrosion caused by a leaky windshield gasket just overhead.

Since you just got your car it's best to have the correct year Valiant technical service manual as you will need it to troubleshoot many items.....usually the manuals are between $25 & $50 on Ebay. I've added to my manual by soaking up any info found here & at the Slant Six Forum making it a greater resource than even the mechanics of the past had.