First, an intercity/highway Crown coach. Note the destination window under the windshield. When I first looked at this I thought it might be a Gillig due to the headlights, but the bumper and the way the front sheet metal is attached make me think not.
It also appears that the floor is higher than a school bus Crown, the basement doors are quite tall compared to mine.
Next, an example of a Crown Highway Post Office:
The box body on the back appears to have vertical sides (not curved like the buses) so I wonder if the cab roof is wider than the buses. This would also impact the windshield glass, to it may be that all of the HPO Crowns have flat glass, which could be formed to the different angle of the "A" pillar more easily. The construction of the rear appears to be consistent with techniques used in the fabrication of truck van bodies of the time.
Here's one that has been pimped out. Not sure I like the flat rear, but that's what a truck body is like, I suppose.
And what is up with these coaches and the chrome bullet clearance markers???
Finally, something Bizarre-O. Crown made specialty bodies for clients. Apparently the Wedgewood appliance people wanted a distinctive freight hauler for their kitchen gear:
I count three front bumpers. Wondering how the driver accesses the cab, using the normal curb door of a bus, or are there driver's and passenger's doors?