Yes it has been demilled, but I’m sure they’re not really supposed to be selling it on there. Just thought I’d post this when I saw it.
There is nothing in the description that tells me that is has been demilled, just that it contains no barel or moving parts. Here in the US, the receiver alone is the important part and this item would be considered a machingun. I do not know about UK laws, but I would guess that this item would be restricted too.
In Germany for example the receivers are all free and just the barrels and bolts are subject to legislation.