My '37 has a trim piece above the door, but it does not continue down the latch side of the door opening. Am I missing a piece of trim, or should I insert the windlace between the door frame and the sheet metal of the cab interior?

BTW, Fillingstation.com has a Cab Windlace Vertical Retainer (http://www.parts123.com/parts123/yb.dll?parta~dyndetail~Z5Z5Z50000014a~Z5Z5Z5AAEOQ~P25.00~~~~S3970NIANH24153214050G~Z5Z5Z5~Z5Z5Z50000014x#) that they say fits vertically between the dash and the floor. What would be the purpose of this?