I'm trying to determine the correct hatch glass for my 72 240z. A lot of info I am seeing indicates that the vertical defroster lines were only in 70/71 model years but further research leads me to believe the change happened in the middle of the 72 production at 1/72 production date. I think the parts book supports this. Mine is 10/71 production date an I think it should have vertical. Does this sound correct? 

 I think the defroster change occurred in mid 71. My early 71 has vertical lines, and I just sold a late 71 with horizontal lines. I believe they were both original.

I had a '72 parts car built about 11/71 with vertical defrost lines, so yes, that sounds correct. 

My car is a 12/71 build and it has vertical defroster lines.

 

 

There is a early 72 near me that has the vertical defroster lines. 

It has only 2,600 miles on it. He just drives it around the block once a week during the summer.

Still has the original tires on it.

 

I have my answer! Thanks!