Hello Allen,
I believe Palo Alto Speedometer in Palo Alto Ca. repairs these and other gauges. They are very familiar with Mercedes gauges. They are not inexpensive, so check on the best price you can find on a new one first. MB dealers do not charge shipping for ordering parts in, if you pick up the parts, and some dealers offer good discounts to club members and vintage mercedes owners. So don't automatically rule out the Mercedes dealers.
check with Caliber Motors in CA. Always have a part number available if possible to make it easy for the parts guy. I am sure there are many other gauge restoration shops around. You may find a better deal if you do a little research.
K&K Manufacturing in Michigan has a nice on line catalog with MB part numbers if you do not have a dealer's parts book.
Some contributors to this site like Dan Caron also sells parts and deserve the business for their contributions of information and years of experienc to this site.
Many of the big aftermarket suppliers are simply ordering some parts from the dealer at their discount and turn around and sell them at list to the customer. After shipping is added The customer may have been better off buying directly from a delaer who gives a discount on parts.
Certain items will be priced better at different suppliers. Doing a little research will pay off!
Joe Alexander
Blacklick, Ohio
