gizmo that single cross bolt on that example is weir, to me. I think the cross bolts, magazine boxes, barrel bands are like the seasons, they change. I stand to be corrected.
When I bought my Cz550 in 375 H&H (Early 2000's) American stock, no cross bolts, sling stud no barrel band but held 5 down. 2 or 3 years later I bought my 416 Rigby, American stock, two cross bolts in the standard locations, no barrel band and holds 4 down in the mag. I am aware that CZ US use two different mag boxs. One will hold 3 416 Rigby and the other 4, or 4 and 5 of 458/375 cartridges. Non had jeweling on the bolt. I have a Safari Magnum on lay-by in 458Win. This has the hogs back stock and from memory 2 cross bolts and barrel band but has the roughest action of any CZ550 I have tried, yet it, in Aust. cost about $800 more than the standard 550 Magnum. Go figure. I got it at the standard price, know the store owner and it has sat there for a couple of years and no it will not remain in that stock or as a 458Win or Lot if I keep it.