Diana model 75 (prototype running boar?)

Diana model 75 (prototype running boar?) 

With thanks to a collector friend for these pics. He says:

"I came across an interesting Diana 75 the other day...it appears to be a prototype of the 75 running boar model. The stock is beautifully made from around 10 pieces of timber, very precisely machined and glued together. The stock retains two of the six of the machined slots found on the regular 75, but from there forward, its running boar, however the fore end differs from the production models, and you can clearly see where someone had second thoughts about the stippling....and removed a patch of it from below the loading port.. There is a small label with some notes on it, and whilst it came with an unused diopter rearsight, there are no grooves machined in the barrel to accept a foresight."