Heater question 37 DB

[johnworden1]

This heater was in the truck when it arrived. Vintage and maker are unknown. No sign of the makers name anywhere. 

My question concerns the 3 vent doors. It appears that they were chrome plated and striped with black 1/8" horizontal stripes 1/8" apart. Leaving a 1/8" strip of visible chrome between the black stripes. 

HOWEVER.......  There is a trace of 1/4"  chrome visible along the bottom of one of the doors. The finish is completely gone on the 2 remaining doors. No trace of chrome or black. I know that all 3 were striped. 

THE QUESTION IS......... where all 3 striped with 1 wider chrome exposure along the lower edge ?   See pic    Thanks    John