Spacepaw is basically Spacial Delivery rewritten as a full novel, with some additional exposition at the end to explain the deliberate retelling of the same story.
In that way it kind of reminds me of the ending of the movie The Abyss when there is a throw away line after everyone has been popped from the bottom of the ocean to the surface. One character says something like "Shouldn't we be dead from the pressure change?" and another replies "The aliens must have done something to prevent that." Basically the script writer was saying "I know, but the movie is over. Go home."
At the end of Spacepaw Dickson says "Yes, it is the same story you read the last time, now go read something else." Unfortunately this longer version doesn't really improve on anything. There are no greater insights into Dilbian, Human, or Hemnoid culture. The characters aren't any less two-dimensional. The universe they inhabit isn't expanded or explored. Its just longer. And that warning should have been put at the beginning, not the end. ( )