Hot Rods Weird cut out in trunk ( 31 Ford Roadster )

There's a weird cut out in the trunk maybe for old gas tank or something else first modified in the late fifties.

 

Maybe to knock out a dent.

Neal

 

That's what I'm thinking. HRP

 

I'm agreeing with these guys^

 

Big rear Z...that's the relief for the rear crossmember

 

Thanks guys

 

My model A had a similar cut out but the car was channeled and the slot was for spare tire clearance.

 

looks like a traditional lightening hole cut with an axe.

 

I Would Say To Straighten The Trunk Lid As Well.

 

I'm guessing this too.