Jet Pack 'top deck' Devil in the detail

Hey all. This one goes out to all the mega accurate and detail wanting Fetts.

I have been studying pack photos and there seems to be a soft curve between the horizontal top deck (where the beacon and stabilizer are) and the vertical up stand on the back. This is a detail I don't seem to notice on currently available 'fan made' packs.

So is this a missing detail, or simply something that changes from pack to pack?

Here is a stunt pack which is about one of the best photos I could readily find to show what I mean.......mostly it is what you can't see - a defined line.



Also, seen here on the ESB pack.




Any thoughts?