Here is the response from the eBayer selling his DE LUXE MOTOR wrench:
Dear wrenchmensch,
Hello Mr. Wickes,
Excelsior Motorcycles had the word "Deluxe" cast into their engine cases, and their V-twins were known as Deluxe Motors.
Thanks, Bob
- redskin-relics
This explanation may be anecdotal. Motorcycle manufacturers, in common with bicycle auto manufacturers, put the names of their companies on their wrenches. This practice has also been followed in the UK where Excelsiors were made. For example, I have Enfield, Royal Enfield, and Rudge motorcycle wrenches on my desk as I write this.