Another mystery item, betcha can’t…

https://www.flickr.com/photos/189102681@N07/shares/41s41i

The thing, made of tool steel, is a one-off item, 3x4x 7/8 inches. The maker spent time making a custom box to protect it, and added the touch of “jewelling” I sent the pix around to our machinists club and no one knew for sure what it did. The key is probably the “knife edge.” He might have bolted it down to a steel plate with four precisely-located holes in it and used the knife-edge to precisely align some work- piece on top of that plate. But only he knows for sure and like a lot of this stuff, it only hits the market when the maker is no longer with us.

 

I'm not sure if this helps any, but it looks like drill bushings in the holes, so I'm guessing it's one of the hundreds or thousands of very specialized drill jigs (fixtures) that Tool and Die makers produce in their lifetime. And as you say, it's likely aligned with the workpiece using the knife edge and one or more of the other machined surfaces.

 

Too bad my late Uncle Herb isn't still around; he was a WWII-era tool and die guy and might have known what it was for. My dad might have too.

 

Here’s a precision angle plate with a few typical accessories used for precisely and firmly mounting workpieces. This isn’t mine. Yet. It would all fit in a shoebox but “used” I’m guessing someone would pay $400+. It is all hand-made and took at least many hundreds of hours and specialized machine tools.

https://flic.kr/p/2mT8TCh

 

Alot of machining if it was as simple as a wood splitter blade

 

Springfld you are correct it is a precision stop for locating parts. The bolt pattern will most like fit any standard pattern 1 x 1 or a 1 x 2.... Someone has taken the time to add a swirl finish. Shows that the owner was a true craftsman and really was proud of their work. Here are some examples of the added finish. https://duckduckgo.com/?q=machining+++swirl+finish+in+metal&t=newext&atb=v255-1&iax=images&ia=images