Stanley plane dating flowchart
Interestingly, Stanley used the same numbering system for the Bed Rocks as the Baileys for the first 2 years of manufacture.
It wasn’t until 1900 that the ‘600’ series of numbers (602 through 608) were cast into the plane bodies.
The collector value diminishes if the Foursquare emblem is missing.
They aren't worth that much anyway (with some exceptions), so I would use and enjoy your plane.
When the frog is in the position desired, tighten the frog screws and replace the cutter and lever .