Queen 1 Factory Sample

I used the search on here a bit, but haven't found much.
Yesterday I found a copy in a record shop which seems to be a Hayes factory sample. I was told it belonged to an ex EMI employee.
Side A has 'Not For Sale' in red letters printed on it.

Matrix / Runout Side A YAX 4623-3U KIP - HUGGYPOO KISSY
Matrix / Runout Side B YAX 4624-2U OFF WITH HIS HEAD

Has anyone come across a copy of this? This must be one of the earliest pressings of the album?

A few weeks ago there was the same type of a record from Queen II on ebay. I remember the white sticker with the red letters "Not For Sale", too.
Such factory samples are very rar I think. Queen II left ebay with more then 100 pounds.

kind regards,
W.

I have actually found a bit more info on www.queenmuseum.com.
My copy plays really well, the cover shows the age though, hence the price of 50£ I guess.

It is the best sounding copy I have now.