Since so many places have these Boonton cars, perhaps someone else might be interested in these window latches. We've been in touch with Adlake who was the original manufacturer and is able to produce replacements. If there is enough interest in these and/or the springs there might be a price break. Please let me know if there is anyone interested.

Greetings:
Several years ago, Valley Railroad, had patterns made to produce these, we made one run (carset). We wound the springs ourselves with a McMaster-Carr spring winding outfit.
They work great!
A fair amount of light machining/finishing/fitting is required.
If interested, let me know via PM.
Be advised that I am currently in California on "The Great American Road Trip" doing research for the 2nd edition of "The Steam Locomotive Directory of North America" and won't be back to Connecticut until May.
Be well,
J.David