Option 591 is a speedometer gear adapter. It is required whenever a 3.90 or 4.33:1 rear differential ratio is ordered. For your RAIV that would make it a manditory option. Option 804 is the export-only speedometer that reads out in Kilometers/hr instead of the US-version that reads in miles/hr.
The book that I have is "The GTO Association of America's Pontiac GTO/GT-37 Illustrated Identification Guide." This is the source that is used by the GTOAA for their concours judging program. If our host, Performance Years, doesn't have it in stock, you can go to
http://www.whitehouse-graphics.com/i...de%20book.html to order it directly from the publisher.
As a car built for export, it is possible that specific tires were installed at the Baltimore plant to meet regulations for sale in Sweden. What those original tires were is a question that may best be answered by the original owner. In your car's case the original tires may have been plain black walls, but I do not have any experience with the configuration of export cars, so I can't say for sure.