I wonder would gluing it down with a little copydex work? I think this is what Silverfox use to glue the body of their locos to the chassis. Anyone who has removed a Silverfox body will know that it breaks away from the chassis cleanly, with little effort, which would mean the 141 cabs should be easy enough to remove, if glued with copydex....
But, I'm only thinking out loud here! Research it further before anyone tries it!