vintage Darn Easy hand weaving mini loom darner for visible patching mending embellishment

I've seen these things 'new' (a Speedweve?) advertised on various social media, but I never knew that this is actually a fairly traditional technique weaving patches right on to the fabric of worn clothes or linens. This vintage Darn Easy is very well made, and comes complete with the original instructions illustrated. It's in very good condition, even has the original box.