Your lantern was made by Defiance Lantern & Stpg.
I have one exactly like it minus the FOK mark & St Paul with Defiance markings & Rochester.
I have never seen a D-Lite size globe marked FOK, but I do have a couple of globes marked DEFIANCE BEST-EVR.
I have a couple of fitzall size globes marked FOK&Co and one marked FOK Cp.
The only FARWELL OZMUN & KIRK D-Lite size lantern I have is marked No 2 TRIUMPH St PAUL and was made by Embury.
My other FARWELL OZMUN & KIRK lanterns are fitzall size and were made by Defiance and have the same fount as yours. I have a hot blast marked No O TUBULAR St PAUL, and two cold blasts marked No 200 COLD BLAST St PAUL.
The earlier lanterns that were marked FOK&Co not spelled out and were definately made by CT Ham. I have two cold blasts marked No 2, and a hot blast marked No 2. These have the old style 9/16 fill cap.
As far as age, maybe someone out there can tell you based on the true manufacturer info.
Email for pictures, too many to post.