Hello Philippe,
I think it is a Crown due to the pattern of the fabric/leather in the seats,
and the swivel seats which I don't think were available on the custom model.
My personal conversion from Custom to Crown has led me to most of the
differences between the two models. The Custom interior also has the off
center "v" shape going down the seat backs. I just bid for the dome lamp on
eBay which is round with a Crown in it, and didn't know of this difference.
Is the dome lamp in the '57-'59 Imperial, Crown round with a Crown in it? The
one in my car is a rectangle with a cross hatched lens. Just wondering if
this is another part I need for my Crown conversion. Don't know if I got the
item yet, since the reserve was not met, but I wasn't about to go higher than
$75.00 for a dome light, but I was the high bidder.
Bill '59 Crown