Our Ford Transit wheels aren't common compared the the 8 bolt dually wheels. I lost a wheel cover nut and quickly discovered how unique they are. My 23TR came with Dicor simulators and their own website doesn't show them. Fortunately I called and ordered a replacement nut (V160F8-EJN Jam Nut/Lug Nut Cover) & an extra nut with adapter. $13 worth of parts , $18 shipping. If your ever in a bind a M14x1.5 drain plug and short length of 1/2" pvc pipe will work.
Mine is on the Sprinter chassis, but the valves for all four rear wheels/tires were inaccessible and one of the inside tires was flat. I had my tire guy, have dealt with him for years, redo them, so all four are now easily accessible, and inspect that flat tire inside and out. Thor asked for a copy of the invoice and actually reimbursed me for that.