I took a look at some of your posts and seeing as how your car was hacked up for drag racing, I think you should be looking at two options. One, you can try to find a whole dash assembly with the harness and cluster. Since you are looking for a 73 it might not cost as much as you may think, esp if it's a standard cluster. The other option would be to work with what you have and use a universal harness with aftermarket switches and gauges.
I was able to get a cluster but none of the gauges worked so I installed modern gauges in their place. However, the cluster did not have headlamp, wiper or panel switches. I’m just looking for alternatives. I don’t want to cut anymore than I have to.