neutral reverse switch or what ?? help

OK, you have a correct relay, that is for a clutch switch OR for automatic

First order of business is to take a test lamp and be sure that you are getting power to the relay "in start." Hook your light to the yellow wire on the relay and twist the key, light should come on. You can do that by just sticking the probe in the back of the connector while still on the relay.

Now see if the other wire really is grounded. With both wires still properly hooked to the relay, stick you lamp into the second "push on" wire and twist the key. If the light comes on, that wire is NOT grounding the relay.

If the light does NOT come on when hooked to the second wire, sounds like your relay coil went bad.

Here's how this works:

The great big stud on the relay acts as a junction AND is one contact of the relay, the square terminal is the second contact of the relay. When the relay is made, it jumpers battery power down to the starter solenoid.

The two "push on" connectors are the coil. The yellow brings 12V "in start" from the key to one side of the coil. The coil needs a ground. ON an auto car, the second "push on" terminal is grounded when the NSS is activated in park or neutral. ON a stick car, that terminal is grounded by the clutch safety switch when you depress the clutch.

The two wires which went to your 4 speed are indeed the reverse lamps.

On early cars with single pin NSS, the reverse switch was on the shift linkage

On later cars with 3 pin NSS, the NSS circuit was the center pin, the revers lights the outer two.

I don't know of an easy way to get your reverse lamps working, perhaps build a bracket to mount a microswitch. I believe Hurst and B*M both have accessory switch kits for their shifters, you might be able to adapt one of those. There might be some guys here with BM/ Hurst shifters not using their switches (using instead the transmission switch) you might put out a want ad after you decide

You can NOT put a 3 pin switch into an earlier transmission. The "rooster comb" inside which activates the switch will not operate the reverse function.