What style is this? Early 49?
Far be it from me to challenge the honorable Mr. Allen, but I zoomed in on your pic and I do not see any screw holes in the metal at the top of the door opening for the early '49 metal windlace retainer.
I am thinking that you have a late '49, and the original c-channel windlace retainer has been removed. Someone may have screwed the early center headliner support on to a later cab.
2 cents.