I have been retrofitting factory-style tachometers into gauge clusters a fair amount lately. In my opinion, the reproduction lenses have goofy looking font, and some of them have the green paint on the wrong side which causes them not to illuminate well at night. My recommendation would be to hunt down an OE tach lens. If you're unable to find one, then another option is to modify your original lens by removing the dummy tach design from the lens (Purple Power degreaser takes the silk screen print off nicely). I can make you a tach decal that gets applied to your lens and looks very close to factory.
Intellitronix makes a printed circuit that is made in the USA. You can find them on eBay at a reasonable price.
https://www.intellitronix.com/produc...flexible-board
https://www.ebay.com/itm/186410506305
The Counterpart brand makes a nice factory style tachometer. Some of the reproduction tachometers have locating tabs that are too big to fit in the OE notches in the back tin, but the Counterpart brand fits well without any modifications. GMCPauls sells the Counterpart brand. You can get an 8k tach from NPD, if interested. It is also Counterpart brand.
https://www.npdlink.com/product/gaug...1969&year=1969