So I have been on here for a while now. Out of all the used x500 series that I have seen listed for sale then and now without a doubt 1000's, you know how many I've seen with a 42" deck, maybe 1. Just went on machine finder for kicks and not a single 42" deck to be found on over 360 used x500 series listed including the x500, x520, x530, x534, x540, x570, x580, x584 or the x590. But yet the one dealer who sells/services these unicorns happens to be the one dealer where your brother works. Again, the Op or you and anyone else can do as they please. But to act like a 42" is a normal thing to see on a x500 series Appears to me that it's only the this one dealership and definitely not a "regional" thing. Again there's reasons why Deere doesn't offer this configuration.The Deere dealer where My Brother Runs the service Department they average 5 to 10 42inch decks a year On the X500 series so maybe in your neck of the woods they don't.