Hi Colin,
If you browse the Web on this cutler you will find a couple versions on their activity.
One is that they were originaly S & J Kitch
en and later changed to S & Kitch
in.
Another and more reliable would be that S & J Kitchin was dissolved in 1916 with the three brothers mutual consent. The former head of the company Thomas Edward Kitchin died in 1917.
But again S & J Kitch
en & Co & Plantation Tools were acquired by Ralph Martindale in 1956.
All these people business was about machetes and choppers.
You may pick your favorite version

.
On the other hand there is a wave of machetes and knives out there produced by S & J Kitchin in the WWII period. Your example should have been made between 1940-1950.
Therefore a "modern" piece, i am afraid

.