It's missing files that are included in the Original mesh by Ben Neal ( bdaneal )
Need the Undecorated EMD SD7/9 from this page
http://steammachine.com/bdaneal/std_frt.htm plus the dependencies pack. Download and install
if using Firefox you may get a load of incomprehensible text when you click download, go file save page as and it will default to cdp, other browsers should be OK. It will save as SD9 Undecorated, may need some files from the DLS if bothered about showing as having missing assets, that one is for use in reskinning as an SD9 or SD7 which is how your faulty ones were done.
When installed, open it for edit and copy the following files from the sd9_undec_body folder into the same place for the faulty locos and commit them.
digit1a.texture.txt
digit1b.texture.txt
digit2b.texture.txt
You can't always guarantee that stuff from third party site will have been created properly or for the version of Trainz you have, these are very old assets, however once the missing files are provided, they look pretty good to me. A bit sloppy having missing files though!
Edit: They all work in TRS19 by the way. Just tested them.
