Vintage A/S strength compared to modern day cologne strength

I've seen it referenced on Basenotes that older after shave from top tier houses, like Chanel, are almost as potent as newer strength colognes or for that matter older vintage colognes. Apparently the strength differences in the 1970's and 80's was not so far apart. One of the vintage Chanel scents that I'm looking for, which has a strength of 60% in the aftershave, is almost impossible to find in vintage cologne but I don't want to buy its reformulated newer bottle because I'm told it bears scant resemblance to the vintage, both in scent and in longevity. The aftershave is sometimes available. Will the vintage aftershave provide a close enough experience to the vintage cologne?