Instrument Services Inc 11765 Main St Roscoe IL 61073 800-558-2674 Rebuilds/fixes original equipment gages such as tachs, speedos, gage packs, etc http://www.clocksandgauges.com/
How many do you need? There's tons of those out there for sale-used. Try Poston enterprises or Year one.
They sell aftermarket. Originals always better. Repro everything is suspect. I have not used 95% of anything repro I have bought over the years because it did not fit/work or just sucked.