I took your advice and took a look at the bolts/nut. 
It turns out that the front one with the odd looking markings looks to be correct with the rounded ball etc. 
the rear however came off as a lug nut...then the light came on. 
The rear has at least a 30mm spacer in place to push out the 11 inch rim so it makes sense that it would have nut.
 
