Actually the 'crown' logo is for King Lock Co. the maker of that Ford key.
For all the most info in one place on Ford keys, coil box, or ignition switch, we have this nice research
IGNITION KEYS
1913 - 1927
By Trent E. Boggess
Dept. of Business
Plymouth State College, Plymouth, NH 03264
It seems that there is a story in even the simplest, most common Model T part. For instance, take ignition switch keys. A key is a key, right? Just make sure you have the right number. Well, maybe its not so simple.
From the time that the Ford Motor Company began using coils and coil box assemblies of the K.W. Ignition — Ford Motor Company design, the Company began to have a say in the design of the switch keys. The first switch key was adopted for production on April 12, 1913 and was given the factory number T-5815. This key was actually an assembly of three parts: T-5816, T-5817 and T-5823. The handle portion of the key was brass plated. Keys were supplied by both the Clum Manufacturing Co. and the K.W. Ignition Co.
The first real change in this key came on December 19, 1916. The finish on the key was changed from brass plate to Raven Finish. Raven Finish was a rust proofing process that was developed by the Ford Motor Company that was very similar to Parkerizing. It left a black, phosphate coating on the surface of the steel that tended to resist rusting.
On May 8, 1917, the key was redesigned. Instead of an assembly of three pieces, the key was made from a single flat piece of cold-rolled steel. The name of the key was changed as well. Instead of “Switch Lever Assembly,” this part became known as simply the “Switch Key” This design was modified slighTLy on June 19, 1919 by changing the inside corners of the “L” shaped plugs to have a 3/64” radius instead of a square corner to strengthen the dies which made the key.
This key's factory number was changed to T-5815-A on February 13, 1919 to distinguish it from the key used on cars equipped with starters. It remained a part of standard equipment until the use of the switch mounted on the coil box of non-started equipped cars ended about August 9, 1922. Thereafter, this switch key was given the designation T-5815-AR, the “R” indicating that the part was to be used for repairs only. (Releases for T-5815-AR)
The second type of key is distinguishable by the round shape of the head of the key. It was a short lived design supplied by the Clum Manufacturing Company. The tumbler notches appear on one edge of the key only. According to factory records, it was used on the first 15,000 cars built with electric starters in 1919. These cars were primarily sedans and coupes and had the ignition switch and ammeter mounted on the instrument panel. Keys were purchased by Ford in series numbers ranging from 1 to 32. Cars equipped with starters came with two of these keys, as opposed to the non-starter cars which came with only one T-5815-A. The Ford engineering records refer to this key as T-5815-BR and it was given the name “Ignition Switch Key” to help distinguish it from the earlier type. (Releases for T-5815-BR) The final and most common key is characterized by a head that is diamond shaped. While it was adopted on Feb. 21, 1919, the records suggest that this key was not used until after April 23. This key was number T-5815-C. These keys were made out of nickel silver and the heads were “pin frosted” on both sides. A smooth 1/8” by 3/8” surface was provided on the back side of the key for the serial number of the key. These numbers ran from 51 to 74 inclusive. The front face bore the word “Ford” in script.
These keys were made by a number of different vendors. On December 19, 1919 Ford specified that the maker's trademark be placed under the script “Ford” on the face of the key. Keys were supplied by five vendors. These vendors and their trademarks are:
Clum Manufacturing Co.
Briggs and Stratton Co.
King Lock Co.
Cabkey Dupree Co (keys have also been observed with Cabkey Dupree spelled out on the key.
Culver Stearns Co.
Cost cutting caused a change in these keys on Jan 16, 1920. The “pin frosting” was eliminated and the front and rear faces of the diamond head became smooth except for the borders, script word “Ford,” trademark, and serial number boss.
The final change to the key came on January 30, 1926 when the material the keys were made from was changed from nickel silver to “S” brass. (Releases for T-5815-C)
(except maybe the very first one I got with the 21?
and odd aftermarket key, marked around the hole ‘Francis Keil and Son New York