IIRC, there are no holes at all, I have since adhered a thin rubber pad I made from the liner to a truck stop briefcase.
The way Joe described it to me, he bought the gun specifically to get the stock, set it in a corner for a week or two...and the glued on super spongy rubber pad wet rotted and kind of slid off. It sounded like the death of many 8-track tapes to me.
It has never truly been fitted to a gun, and it's a bit of a bear to actually find a gun that fits into it....yet there is still a huge amount of gap at the stock ferrule. The AKesque handguard is fun to get to play nice with a gas tube as well. I don't think that is pictured in the above thread though. Per Joe's instructions though...it must be used on a gun with a bayonet, since it is capable of either spike or blade. It currently has an M44 bayonet, with a straight eared Russian handle, to keep it upright...but it will accept a blade just as easily, even on a spiker.
I think it's a prototype,or possibly the only one left on earth. Piers Dev is a stock company from Australia...but, since the govt. there defrocked the citizenry of their arms...they never really had any internet presence. It is a total mystery....and best of all, It's pretty neato.
As far as I can tell, it is a plastic rendition of a Sporter stock, just with a traditional magwell and a bayonet slot.