As I posted earlier; Snynders provided me with a replacement APCO temp. gauge to test and exchange if needed.
I used a digital temp. probe which is very accurate and compared gauges.
I was surprised how accurate they actually were! At 160 degrees they both were within 2 degrees of the expensive digital probe.
Next: I tested the Moto Meter against the temp probe. My control water sample read 145.6 degrees. The motor meter was approx. 1/4 inch off the bottom.
So while my APCO is reading the temps leaving the engine... @ 180-190 degrees... the Moto Metter never got much above the 145 degree mark.
So it goes..... Sometimes with a Model A a Temp. gauge is way too much information !