I have always enjoyed this model, from its first release to the Suprefast Transition toy, it is rock solid pretty in its displayability, and the boxes it lends itself to are just splendid. Whenever i am at a toy show and see this model present, if its priced at book or a bit above, and its mint boxed, i buy it. its one of about 30 models i never pass up at toy shows for 'buy at book value' mint boxed.

http://i5.photobucket.com/albums/y152/SteveCameron/DSC02338.jpg

http://i5.photobucket.com/albums/y152/SteveCameron/DSC02337-1.jpg
:)

There are 2 baseplate variations for the regular wheel, no 59 or no 55 & 59 -I have both.Then there is the transition from decal to sticker - does the rw exist with sticker or SF exist with a decal? Although the SF wheels are a little oversize I like the SF best.Shame the police version of this casting (with red or blue light) didnt last long enough to be a SF

i have the rw version with decal and sticker sides, it didn‘t focus sharp on the bottom model which is the sticker.. don’t know about the sf with decal, could be out there somewhere.
http://img527.imageshack.us/img527/9799/firechiefreg59sideaqw2.jpg
i have the sf with the large and small diameter five spoke thin wheels. the small wheels do look a little better, weren’t there some more models that had these two styles of wheels?
http://img166.imageshack.us/img166/4681/firechiefsf59wheelspj8.jpg

A great comparison of wheel variations moutain, thank you for setting them side by side for us to view. another example off the top of my noggin is the #13 Wrecker Truck

http://i5.photobucket.com/albums/y152/SteveCameron/DSC01413.jpg

not a great picture tho. the larger diameter tire is on the left, with the smaller version on the right.
http://i5.photobucket.com/albums/y152/SteveCameron/DSC01415.jpg

The 13 SF also came with large 4 spokes on the rear (as fitted to the 70 Grit spreader and Refridgerator truck amongst others).Just about anycar fitted with solid skinny SF wheels could have hollow wheels 1mm smaller fitted later in production.Purple 22 Pontiac GP is a well documented example on ´the other forum`

that’s what i was thinking too. i don’t know if there is much interest in that variation, but some as you said look much better with different diameter wheels.