I am right there with you!!! I am a DL who is mostly just a DF (diaper fetishist) with an addiction to the kind of plastic found ONLY on those 70s style Pampers and generic diapers which featured diamond-embossed texture/detailing in the plastics (like you can make out in the high-res photos I just posted).
But right up there next to my addiction to the plastic itself, is the perfume used in those 70s to 80s vintage Pampers and Luvs diapers. Many others on this forum have expressed a LOVE for that heavenly diaper scent of yesteryear as well.
My degree in psychology has taught me that scent is one of the strongest imprinting mechanisms that exists for humans. Since that diaper scent is linked to the diapers we wore as babies for the first few years of our life, it is no wonder that, now as adults, many, many ABDLs are also addicted to that out-of-this-world diaper smell.