Not all ghost signs are created equal, and this is our first example of a sign whose company name is tantalizingly close to, but not quite, legible. I can make out National and Co., but I've not been able to divine the word or two in between. We're still in the historic Automotive District, and the last two letters of the word before Co. look like they could be "us", so maybe it says "bus." The sign appears on the side of the building at 1222 Harmon Place.
If you can do better than me in making sense of this, please let me know in the comments.