didn't you ever notice at in the open shots? the letters on the out door billboard were always being re-arranged (i the think it was actually farty towels one week.. )
Miss that detail did you in the open credits? Ha, go back and rewatch them! that is one of the reason python humor holds up. there was so much crammed it a show, sometimes you'd miss a bit.. like the title of the books on the coffee table , or the newpaper headlines, or the art on the wall.. or the billboard in the front entry way, by the parking lot/car park was an anagram!