Chisel struck roof rivet on late 60's Ford GT

[Tinman]

I just came across this late model regular wheel Ford GT with a chisel struck roof rivet holding in the window insert. As soon as I saw it I recalled another recently discussed model where the chisel marks were not done in a common manner. This one has four strikes and they go side to side. None of them line up and must have been struck four times. I just opened up the model and the base rivets were factory perfect, only the roof rivet is chisel struck.



Closer:



It's the newest non-preproduction model I've ever seen with a chisel struck rivet. This particular Ford GT is a fairly late production model with a light blue paper label.



For those that have a hard time seeing my crappy pic, here's a drawing showing the directions of the chisel strikes. In my drawing a couple seem to line up (my bad making the drawing) but on the model they do not line up.

[Tinman]

I opened up three of them today The first one is in the preceding post, the next one was a normal spun rivet and the third one has this more usual chisel struck roof rivet. This last one was made earlier as it had a decal. This one failed to hold the windows in very tight as the rear window had dropped noticably.

[MatchboxFreak]

Hello Tinman
Is it common for the Ford GT window rivets to be split instead of spun?
Was it common practice for any other casting?
The second split example you showed seems to have 7 lobes; could one crack be from metal fatigue?
THanks for showing.
Kurt