Your Junior Wagon Lamp takes a Dietz No.857 globe. Modern replacement globes are available from several sources.
You can simply Google search for Dietz #857 globe and you'll find them. Depending on your location, the best sources are W.T. Kirkman in the West or Leahman's more Eastward. These modern replacements are however Chinese made and are of very thin glass. Since you have an antique lantern you may want a globe that is more like the original that was in the lantern when it was made. In that case I would recommend purchasing a globe from W.T. Kirkman who sells their own brand of globe made of much heavier glass. The links below are to the W.T. Kirkman catalog for the modern Dietz replacement and the W.T. Kirkman #857 "Little Champ" globe which is the same dimensions as the Dietz Junior globe.
Dietz Junior Globe
W.T.K. Little Champ Globe