You don't say whether trunk or rumble. These pictures are from a 29 roadster with a rumble seat.
My outer panel below the rumble lid is a repro, but I had original horizontal and vertical brackets to go with it. It took lots of banging to get it to fit even after I had the manufacturer fit the panel for me by bringing my body down to their shop.
Here is a repro 29 panel (smooth without a lower ridge). Note the top of the panel is straight. I somehow managed to get the rumble lid to work with this panel although it is not perfect. Bad thing: there is more wow in the middle of the panel gap. Good thing: at least it is not a 30/31 panel on a 29:
My 29 came with this original outer panel below the rumble lid from a 30/31 with the raised band on the bottom. Note the top of the panel is curved like it is supposed to be:
Here is a picture of the curved inner panel I took out and replaced with the repro. It looks like to me someone hacked on a trunk inner panel and put it into a rumble trunk. Note it doesn't have a hole in it for the bolt to attach the rear spare or a rear spare bracket:
The things you find when you buy a Model A! My roadster is basically a bunch of parts from different cars thrown together with wrong parts mostly fixed by me as I'm painting it. I'm not a show car person however and the purist might find lots to complain about my car like they did when I drove it to the local Model A club. Note, I'm not a member of the local Model A club after hearing everything that is "wrong" with my car.
This is the bracket on the underside of the curved inner panel. There is a bolt that goes thru the bracket to hold the rear spare tire on. My curved inner panel is a repro that fits very good.
These are the brackets on the panel below the rumble lid. Sorry about the painters tape as I am currently paining it. The horizontal bracket goes the width of the rumble lid and the curved inner panel attaches to it. The vertical bracket has a hole in it for the rear spare bolt to go thru.
It would be best to find original pieces for both these brackets. The repros look nothing like an original and it puzzles me how they could be made to fit.
No angle iron is involved with this set up.
Position the seat riser on the cross member for d_Seymour: