I haven’t been able to confirm whether or not this is authentic, but I suppose the fact that it very well could be is in some ways more significant.
Update: A commenter provides a link to a copy in a Cornell University library collection of political Americana.
ERIK–In my view, what is significant about this image is that labor was strong enough in 1956 that Republicans had to lie and say they respected it. They didn’t believe any of this in 1956 and they don’t now. But that they had to say to compete nationally, that is amazing from today’s perspective.