For me it had to be back in 2007 when I received a BMM Tiberius Kirk replica. The smell had a subtle similar quality to lemon based dish soap.
Instead of the Smell of Napalm in the Morning how about:
The Smell of Latex in the evening
Some of my Nightowl masks had a pumpkin spice type of scent to them.
Any mask that comes from JC’s green room. Pure old school Halloween look, feel & smell 
I love the smell of vinyl masks, like the don post skulls, tor johnson etc. ive got a black vinyl hagatha as well
Oddly enough, my first mask, my ToTs H2 Deluxe mask has this unique latex smell to it that all my other masks don’t have, and it’s my favorite.
Back in like 2005 I received my Warlock SE from CGP and it smelled just like milk chocolate. It smelled like that for weeks.
My first Psycho in 2009. It had a subtle sweet smell to it. It always brings me back.
Well as for masks in the mail, I would say my NAG 75K Castle hit me with a distinct pleasant smell. It was my first NAG mask and so that smell goes hand in hand with it.
But there is another mask smell that I remember from back in the day, that’s the distinct vanilla smell of Fun World masks. This is LONG before Scream was even a thing. I owned a few Fun World masks years before Scream came out, including a green ghost mask, and a couple of the other designs.
Sadly, it seems in recent times that they no longer produce the masks in the same way and the smell is no longer there in the newer masks. The last time I remember those having that smell was in 2011, when there was a cheaper 5 dollar version of the Ghostface mask at walmart. That cheaper version was more in line with the original old way they had made them back in the day. The newer way they make them was also available at that time, but it was a 10 dollar mask.
Now today, it’s only that newer version you see everywhere, so the classic vanilla smell is long gone. But when I see Ghostface masks, I think of that smell. Good stuff.
HSS masks would smell like cotton candy. I have 2 masks from Darkside studio that i’m waiting to open on Halloween night and I can smell them through the box they’re in 
Nice, what did you get from Paul? I picked up a Deluxe pt 4 Jason and a Lost Boys David last year. Waited too long to get something before Halloween this year, but thinking about a Howling werewolf or Wicked 1990 Pennywise for my next order.
maybe this guy was wearing it?
They say many of the old Warlocks smelled of chocolate.
Sent you a message 