1949 Ford drip rails question

Hey there, guys,

Question on drip rails: I have a '49 Ford Club Coupe, and halfway back on my drip rails--near the B-pillar--there's actually what looks like a stamped slit in the bottom of each drip rail.

It happens on each side, and I have to say--they look factory-made. Is this some lame idea they came up with in '49? Because my drip rails don't look rusted out; there's no rust-through anywhere else near that area.

Please let me know.

Thanks!

 

TTT

C'mon, guys. Someone's gotta know what I'm talking about.