Well with 118 views and no comments it must be too rough for any value whatsoever. I’m kinda figuring with the large size and loss of enamel value somewhere around $400
Really clean examples of these have recently been selling > $4000. Here's ours for comparison. I value it > $2000, mainly because of the chips along the top, including 3 nail holes. The only issue I have with your example is whether or not that big vertical crease was due to a fold. If not, and it's solid, I wouldn't be surprised if there are plenty of entry-level collectors who would pay $800-1000 for that sign.