You only needed to write 97 on the checks back then. As far as I remember all bank checks came with the first two numbers 19, pre printed on the checks. That was a sort of banking convenience that people could save pen ink by only having to write the last 2 numbers in the date. That was also the reason that caused the Y2K crisis! Come January 2000, the banks were worried that people would write the date down as 1900 instead of crossing out the pre printed 19 and writing 20 over it! That means that the check would be 100 years old and should the banks still honor it not knowing if the funds would still be good.
You only needed to write 97 on the checks back then. As far as I remember all bank checks came with the first two numbers 19, pre printed on the checks. That was a sort of banking convenience that people could save pen ink by only having to write the last 2 numbers in the date. That was also the reason that caused the Y2K crisis! Come January 2000, the banks were worried that people would write the date down as 1900 instead of crossing out the pre printed 19 and writing 20 over it! That means that the check would be 100 years old and should the banks still honor it not knowing if the funds would still be good.