Technical 28/29 model A pickup bed question

I am in the process of replacing the bed wood in my RPU. The bed planks are pretty straight forward but the bed to frame sill pieces are totally gone. Does anyone have dimensions for these. They appear to be 2× 3-1/2 hardwood but like I said I don't have anything to go by.

 

The sill boards are readily available for under 200 bucks. They have some reliefs cut in them for clearing some bumps on the frame rails. Check with Ecklers and CW Moss. I think Brookeville Roadster has them as well.

 

I see that they are available but by the time they land here with exchange and shipping I bet they are over $400 Canadian smackaroonies.
They don't look complicated , I'm sure I could cobble a pair for well under $100 .
I just need the measurements.

 

This will give you overall dimensions. Not an authentic ford part as it 2 piece but the other details are correct. Left and right are mirror image. All narrow bed pickups are the same.

 

Thank you very much!
That's what I'm talking about.
Cheers!