Hmmm 3 hours, 80 views and no response. I'm researching the net and found one similar but no reference to a make. Would this be an early universal speedo?
No, SW "universal" speedometers were almost always round. This looks similar to an early Es***/Hudson speedo.
I see similar styes in that era and earlier. Looks like GM used AC brand. A lot of car manufacturers during this era as well. Might make it tough to dial in a make.
Looks can be deceiving on some of these panels. Often there is a round gauge behind the square cutout in the panel. Here's a '29 Graham Paige panel and the speedo that came out of it.
ok...found this panel with what looks like your speedo. No info on what it came out of, but it's a start...sorry, very small pic.
I just googled 1920's stewart warner speedometer, and started going thru all the pics. This pic came from a completed ebay listing, but the guy didn't know what it was...I'll keep looking...got plenty of beer and chew.