Bob,
I found this on E-bay, an HO undecorated 'SAL' Stump Gondola, notice the slots in the sides, towards the bottom, the picture has to be enlarged, for a clear picture.
1http://www.ebay.com/itm/Seaboard-Air-Line-SAL-HO-Stump-Gondola-Undec-/12174200377
Ralph