Those Iron-cross lights were not available in the time period you want your rod to emulate!
Let me suggest a set of '32 flatlens original type stainless lights (use 2 RH if you're not going to light the plate with the tailight). Mount these under the edge of the bed using 28-29 Model A pickup brackets. For a unique touch, drill the lenses carefully and install a 34 Pickup Hood Side V8 emblems in each lens.
Other options depending on your choice of mounting place includes 51 Pontiac(the round ones), 41-48 Chevy(the rectangular ones, 42-48 Ford(the oval ones), 40 Chevy(the roundtop, pointed bottom ones), and a really different alternative to the Ford teardrops is the 39 Plymouth teardrop(but very hard to find), 58 Impala(the round ones), 58 Biscayne(2 lense with rather bulky mount but might be interesting sunk in a panel under the tailgate, just an idea).