If you want an original dash I recommend a contact of mine I can get you in touch with who will sell you a rebuilt original tach and gauge cluster.
I also have a contact who could sell you a rebuilt original under dash harness. "Harness tweaker"
You can also buy a look alike volt meter to replace the amp that they now produce, (an exact copy print and all) I still recommend an oil pressure gauge. The tach man has an oil pressure conversion for the factory amp gauge if you go that route but he has the patent on some no one else can make it.