I have one of those. The tip is blocked, so I suppose the blade would be inserted from the bottom tang area.
Within the frame/tang of the thing is a spring-loaded plunger which, apparently, shoves the blade forward and locks it in.
It would have to be a thin blade with no spine on it. I can get pics tomorrow, if interested.
Check! I looked again and mine is not at all like Joe's
Perhaps it will take regular Weck blades?
Don't cut yerself! :nono: