Hi,
I wonder if the snack shop at the LaSalle location is indeed a Howard Johnson's restaurant rather than an independent.  This unofficial website suggests they have the complete 
inventory of Howard Johnson's restaurants.
When I lived in Maryland, we had a Howard Johnson's in town.  We often went there for ice cream.  I liked their macaroni and cheese, though I have wondered if I would like it now.  This Howard Johnson, and I think many others, had a large freezer case with packaged frozen entrees from their menu.  I was always somewhat miffed my parents did not buy any of these frozen entrees I was so curious about.  Now after reading this article and knowing who was in the HJ kitchen, I am doubly miffed.
The last Howard Johnsons restaurant I knew about in this area was just off Touhy Avenue near the Leaning Tower of Pisa.