Basically nothing is known about this rifle in terms of who created it or when – but it is a pretty interesting example of an attempt to convert a bolt action rifle to semiautomatic. This rifle began life as a standard Dutch Mannlicher rifle. The conversion was done here be splicing a Lewis Gun gas piston/op rod to the side of the barrel, and then modifying the bolt to work like a Lewis bolt, with a fixed firing pin and rotating cam in the bolt body. To top it off, the gas piston is driven not by a drilled gas port, but rather by a gas trap extension on the muzzle.
The bolt conversion work seems to have been done pretty well, but the receiver extension could hardly be any more crude. It cracked and broke off the original receiver at some point, and has been poorly welded back in place (mostly).
Thanks to the Dutch National Military Museum for allowing me access to film this rifle!