IHC RPO car detail- what goes here?

I picked up a bunch of IHC passenger cars pretty cheap. I knew they would need work, but I’m thinking of making my first attempt at custom painting and wanted a set that I wouldn’t cry over if it all went bad. They already are converted to body mount kadees and weighted correctly.

I was looking at the grab irons and such that I have to add when I came the the RPO car. As in the picture below, there are three big holes near the door. By looking on google I figured out two are for the mail crane, which I’ll have to scratch build, but the third has me puzzled. Can anyone tell me what goes in it?

Gidday, [#welcome] to the forum.

Looking at this…

http://www.youtube.com/watch?v=IirDQzgzlQg

…I’d guess that its the attachment for the diagonal stay on the mail hook assembly.

Cheers, the Bear.

Checking my IHC mail car the hole in question is for the bottom of the mail hook assembly.

The mail hook spans across the door and is also attached at the bottom which would allow it to swing out.

Hope this helps