Here is a Woodcrafters Series Router Letter Template Set from Vermont American.
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Create custom wood-engraved signs with the Milescraft 1212 SignPro. The self-spacing characters fit into the adjustable clamping system without having to make any measurements. Simply affix the character templates and start routing to create uniformly spaced letters and numbers. This sign making system also includes TurnLock as an integral feature on the BasePlate, and the bushing exchange is tool-free, hardware-free and takes only seconds.
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WOOD CRAFTERS SERIES ROUTER LETTER TEMPLATE SET
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Vintage Sears Craftsman Router Template Set 9-25182 Letters