COE How rare are early Ford cabovers?

I hope to build a 1938-47 Ford COE. '39 is my first choice. I would like to know how rare are these? Production numbers?

 

Production numbers don't mean diddly, you just have to keep your eyes open and be in the right place at the right time with the $$ to spend.

 

I bought a ford manual at the portland swap-meet because it was canadian and had some ford c.o.e. info in it. in canada c.o.e.'s were not produced in 42-45 and production started in 39.