I know exactly which place you are talking about on I-80 in Iowa.  We went by there less than 2 weeks ago.  I am thinking that was a Stuckey’s restaurant.  In fact, I seem to recall more than 1 Stuckey’s restaurant along I-80 in Iowa back in the 70’s/80’s.  Although I recall the name Nickerson Farms, I can’t remember where I actually saw one when they were open.  I saw an old abandoned Nickerson Farms along I-10 between Tucson and Phoenix in Arizona last Fall.  I wonder if the owner of that adult bookstore would know what the building was originally?