Wb, I may have a Mercury tailgate just like that. It was my Dad's. There's no truck anymore but I have the tailgate. Of course, it's not as rare up here in Canada.
I used to remember a few Merc pickups when the wheat whackers came through but not many made it this far south to stay. A 57 Merc big window custom cab is still one of my most wanted.
The Chrysler is a 331 Hemi. A huge boat and not particularly captivating styling but it needed saved. Power steering, windows and seat were the stuff of dreams in 53.
I got a muddled up title with it so it will take my towing company a couple months to straighten that out. They are the only ones who can do it now.