Why does it need to have been “blessed” with Gibson’s halo for you to see it as significant?
If it wasn’t associated with 617 Squadron.. well, so what? It is an important piece of equipment in its own right.

If the sellers want a price premium based on its alleged association with 617 squadron, them obviously it would be nice if it is as claimed. It’s called honesty…or lack of fraudulent intent if you will.
Otherwise, as I said, it’s a neat old truck without any special provenance. Is everything that had anything to do with WWII “important” (to use your word)?
Of course not…especially if there are many about. A Jeep that spent the war being driven by a sergeant for an unknown colonel isn’t necessarily “important”. One used by the SAS, Patton or Eisenhower…that would be a different story.