Baffling Unknown Mystery Cast Iron Device...What Is It?

[taal_volcano_museum]

Unknown Device...I've Had This Thing For Years...Never Could Figure Out What It Was Used For. Any Ideas?...Solid Cast Iron, Looks like a Spatula / A Blade with Handle and Threaded Screw Holes / Measures 15 Inches Long  / Total Weight= About 1 lb. (0.80) / Holds 28 Threaded Screw Holes (Large To Small) / Blade Thickness Measures 0.25 of an Inch and Tapers Down To 1/8th of an Inch / I'll Check Back To See If Somebody Can Solve What This Mystery Device Is.
Thank You In Advance For Any Input.

[eburtonlab]

Antique screw plate:

http://www.markelliottva.com/wordpress/2015/06/tools-toys-june-15/

https://www.ebay.co.uk/itm/ANTIQUE-CLOCK-MAKERS-SCREW-PLATE-GAUGE-SCREW-THREAD-OLD-TOOL-12-13-32-inc...

https://www.tooltique.co.uk/shop/vintage-thread-gauge-with-unknown-makers-mark-clock-makers-tool/

https://www.worthpoint.com/worthopedia/antique-screw-plate-peter-stubs-168198979

[taal_volcano_museum]

Thank You Sir...You Nailed It....Mystery Solved.

[danny_j_sales]

Answer prior to mine looks like the CORRECT ANSWER. Without initially knowing that I was  (and will) suggest that it seems like some type of screw/bolt thread size and pitch gage. Maybe even a "clean-up" tool to remove dirt and corrosion from threads. That feature is deduced from the slots at each hole, similar to a thread cutting die. Modern versions of this type of device are often found at the fastener department of hardware stores. Helps provide customers confirmation of the screw thread size they're looking for.

DJD

danny_J_sales

Vintage MOTORS n MUSIC eBay Store