I got these from a camper shop that was going out of business. I bought a bunch of stuff to use on my TD, and these came with it. I have a couple of different sizes and colors/styles. They are all brand new, and made of vinyl. Email me for more pictures.
I have 2 different sizes availible for 12" tires, one for a 21 1/2" tire diamater which fits a 5.30 x 12 or 4.50 x 12 tire, and a one for a 20 3/4" tire diamater which fits a 4.80 x 12, 4.00 x 12, or 20 x 8.00-0 tire. They are blue with a Viking silkscreened on them (were for Viking campers). I also have a black one and a brown one that are for a Jayco and have an eagle silkscreened on them, for a 21 1/2" tire diamater which fits a 5.30 x 12 or 4.50 x 12 tire.
I have a gray one for a 14" tire, that has a "Sunlite" sticker on it, which could probably be removed easily, it fits a 27" diameter tire (7.50x14, 7.75x14, 8.00x14, 8.25x14, E78x14, F78x14, G78x14, P195/75Rx14, P205/75Rx14, or 6.40x15)
$15 each, includes postage (priority mail) in the US.