Need Model A grill shell measurements

I was hoping someone could get me a measurement of the opening of a '29 grill shell. I am going to build a grill insert but I'm at work and my shell is at the shop.Height and width of opening only.

Thanks,
Chris

 

mine is
width 18 near bottom, 18 1/2 near centre, 17 near top
height is 19 , about 3 inches in from outer edge of opening

 

Thank you.
If the insert turns out I'll post pics. If not it'll go in the s**** bin.