For what it's worth, I have an 1969 Z/28 without a factory tach. It also has no console. Also have the chassis broadcast sheet, actually only about 60% of it has survived life under the back seat. The car is an 05A car built in LA. I've talked to the original selling dealer who confirmed for me that they typically ordered Z's for inventory as cheaply as possible thus my car came without most options.
Yeah Grody Chevrolet here did the same, also with Impala Nova's and Chevelle's. Ton's of low option SS badges all over the lot those days.