I'll add my vote for the separation of the glass layers.
As for this being only on MB - just visit any salvage yard with early 1970's vintage or earlier cars - you'll see lots of it. In fact, if you go to a lot of car shows, you'll even see it on some vehicles that aren't yet fully restored.
Just my .02
'87 560SEL 267K (177K on motor) Blue/Blue
'98 Buick LeSebre 60K (wife's car)
'56 Imperial Sedan 124K
'67 Dodge Monaco 130K (Sold)
'87 Chrysler 5th Ave 245K and going strong (sold)
'73 Plymouth Satillite 175K (sold)
'96 Chrysler LHS 80K (totaled)