[SS427]

I was right on my assumtion of the build plant and based on "L" on the cowl tag it appears to be an SS though that is only speculation at this time. If this car has been unmolested as it appears and based on the build date I would bet there are at least 3 sheets in that car. One in the front seat back (push on the seat back and you may feel it on the drivers side), one in the bottom rear seat and one in the passengers front fender and there may be more as I have found them in other places on Leeds cars as well. It is VERY rare that they are not in these locations on the Leeds cars around that date.
Rick