thats whats weird about these they mount that way, or on the side af the cowl of a big truck... first time ive seen these
the marker lights should be facing up, i think those were common on rigs like you said, so that explains why the mounts are at the wrong place for a rod. but anyway, the positioning looks perfect!
Aman: Maybe you could switch the lights. Try them on the other side. I concur; move the marker/signal lights to the radiator side would clean the whole deal up. Interesting application of cool old parts.