I lost and replaced the center caps on the wheels several times. They are made of cheap plastic with micky mouse clips to hold them on.
Finally I decided the cost wasn't worth it and removed them all and run without now and it works just fine. The last ones I purchased were around $25 each plus shipping.
Id have to look, but may have a couple good caps in the garage....I know I have several that broke and won't stay on.
My XT-276 uses the same wheels as you have in the picture - black wheel with the 'chrome' double stripe.
2012 Fun Finder XT 276 Toy Hauler & Harley Davidson Ultra Classic with Condor wheel chock
2014 Dodge Ram 2500 AT 4X4 Crew Cab 6.4 L Hemi, 373 gears, tow package, Rambox option, Revolver X2 tonneau cover, Equal-I-zer anti-sway hitch.