Your cars are newer than 67, not older. VIN nrs. etc. can be found here.
https://www.thesamba.com/vw/archives/info/bugchassisdating.php Not a lot of help for the 70's it seems. Info at bottom of page.
End? of July 71
Chassis 111 3 143 119
_ D_ 0 836 000 - 34hp
_ AB 0 350 000 - 1300/40hp
_ AD 0 360 022 - 1600/50hp
_ AE 0 568 000 - 1600/50hp
_ AH 0 000 001 - 1600/48hp
End? of July
Chassis 112 2 961 362
_ D_ 1 000 001 - 1200/34hp
_ AB 0 699 001 - 1300/44hp
_ AD 0 598 001 - 1600/50hp
_ AE 0 971 063 - 1600/50hp
_ AH 0 006 900 - 1600/48hp
_ AF 0 000 802 - 1600/46hp
End? of July 1973
Chassis 113 3 021 911
_D_ 1 039 792 - 1200/34hp
_AB 0 820 427 - 1300/44hp
_AD 0 749 788 - 1600/50hp
_AE changed at 1 000 000 to AK 0 060 039 - 1600/50hp
_AF 0 034 850 - 1600/46hp
_AH 0 056 934 - 1600/48hp
Mike
Texas
Nov. 1947 +
Febr 1949 shell