I see that M37's have 2 styles of instrument panel lighting. The kind in my truck has the flat domed covers like in the first pic. But I see other M's have the type in the second pic. I'm guessing this style was used in later production? Am I right....did the M37 instrument panel lights change at some point in production....maybe the second style used in the B1 version or Canadian versions???
By the late 50s the mil standard was the second light shown. Therefore when the B1 model went into production it was updated to what was then mil standard. So both are correct depending on which model truck you had. M37 or M37B1.