Ok So I am 6 Years Into my restoration on my 1968 911,and of Course still learning more about the idiosyncrasies of these early cars.

Its well known that '68's had a few unique one year only items like Rear view mirror and Engine Grills Etc.

Then there seems to be some more changes like an early vs late Engine grill for a 1968.

My questions to experts is:

Did all the Hard Window Targa's in 1968 supposedly have vertical defrost lines too? I have searched all of google images and all the pictures from the High End Auction houses
for 1968 911S Targas and they ALL have the Hard window with the Horizontal Defrost Lines. Is the vertical lines on a Targa Window a
Urban Myth?

My 1968 911T Targa has a production of May 27th of 1968 and per the Kardex had a Tinted Heated Hard Targa Window.
Was it supposed to have verticle defrost lines? I have only actually see one picture of a Coupe which had the vertical defrost lines.
I have yet to even find a picture of a Targa with Vertical Defrost lines?

Lastly its it possible they could have gone to the later more common Hard window with the vertical lines late in '68 Production year?

Please chime in.