Fritz Hansen Serie 7 Chairs - Which year are my chairs from?  

The 1163 on the label denotes November 1963 as the date of manufacture.
As for value, this board isn't for asking for appraisals but you can determine value easily enough by looking at sales and auction results online for this chair. You may have to track them over a few months if there aren't a lot available at the moment, but it's a pretty common chair so it shouldn't be too hard. (Toss out the super high end sites like 1st Dibs so they don't skew your results. 1st Dibs prices don't reflect the regular market very accurately.)

The trouble with upholstered chairs is that it is difficult to tell whether or not the seat backs have been cracked until the upholstery is removed. Cracked chairs are not worth repairing and restoring, in my opinion.

I agree with you Woody, if the back is soft or broken i would never spend the money on reupholstery.
But if they are still hard the chairs are valuable enough to get them redone.
One thing i noticed in the pic though is that there is one leg missing.
Is that correct Nadine?