Go to most any lawn mower repair shop, and i'd bet you can find a used wheel to fit your machine.
You can google Craftsman Lawn mowers, and they can get ya hooked up to the correct web-site. A word of warning--you can buy a lot of gas fer yer car, with the money you might have to pay to have a wheel sent to you by Sears/Craftsman

Rusty: I would normally agree 100% about Sears Mark Ups . However this Spring when I fired up the Ole White Outdoors Quantum XTE I noticed a slight miss and very minute metallic noise from the recoil / flywheel location . Upon inspection all seemed sound mechanically blade orientation tightness also recoil assembly appeared fine . So did the flywheel tightness . Therefore removed the flywheel inspected the key , sure enough it had rotated ever so slightly. Low and behold my spare key had been used on my Son's B&S the previous fall. Saturday afternoon all the Local Small Engine Repair Shops are closed by Noon . I reluctantly drive to the Sear Repair & Parts Depo , to my surprise they have the correct B&S key 75 cents . Similar keys from local jobbers and aforementioned Small Engine Shops had Gouged me $1.50 - $2.00 within previous 3 yrs. I picked up a six pack of the Little Devil's . Was about to walk out the door when I eyeballed their Trimmer Line Priced $4.00 Cheaper than the Local Canadian Tire Box Store WTF is up with that ! I actually asked the Sale Clerk if the indicated Price was Correct . Goes ta Show Ya there is a Exception to Every Rule Bro ! Not Often at Sear's I must agree but in this case I was Happily Surprised lol !

I do not shop at Sears much anymore, but did at one time. I have found parts at their part's department for items that they carried ten and even 20 years ago for delivery on relatively short notice. I'm sure that it is not cheap for any company to keep such a parts inventory and many companies today, don't.

EVD: Had the same experience with a Older Craftsman Snow-Blower I picked up from a Buddy who does backyard Small Engine Repairs. I required a replacement Chute Cable and some misc mechanical items a few yrs down the road.. To my surprise Sears had them in-stock and at a great price. I stll stay away from their Tools and Clothing , since they have a crazy mark up on most items that I find better priced elsewhere. I usually price check but in both these cases I was captive to Sears due to Local Jobbers Store Hrs lol .