If this is for a Cutlass, they are very simple to make. Here's a few pictures of how I did one years ago.
I used a stock metal gauge face piece to make a paper template.
This is the backside with the template inside:
Then used templates I cut out for my gauges and moved them around on the paper template until I was happy with the layout and taped them down. The gauge templates have the centers marked for the next procedure.
Traced the template out onto a sheet of aluminum and also center punched the center of the gauges as well as the indicator lights.
I then take the stock clear plastic gauge cover and cut the front of it out like this and paint the rest of the plastic black. This keeps you from seeing inside the dash from the sides:
I also take the stock plastic "bucket" piece in the back that has the printed circuit board attached as well as the lights and remove all of that stuff then cut it for clearance with the gauges:
Then the aluminum piece I riveted to the stock metal gauge face after cutting the face and leaving an 1/8" or so lip around for the rivets:
Everything bolts back in just like the stock cluster:
That was my first attempt 7-8 years ago but I used the same technique for my latest gauges but just did a few things differently. For one I used steel instead of aluminum and just tack welded it to the stock steel gauge face piece so that I wouldn't have any rivets showing. I also used Deustch connectors in the dash to make disconnecting the cluster very easy.
The new cluster:
I also found some nicer LED's for the turn signals and brights.