It would be very helpful if the stock item label template could be customised to fit standard avery labels (we use the ones with 27 per page as per the ones used at amazon for our FNSKU stickers). Linnworks can't seem to understand how to make them fit onto the page even though the label sizes plus margins/spacings add up to the size of a sheet of A4. In fact the labels that Linnworks want us to use (and only seem to be able to comprehend) are bigger than some of our products!
I have spoken to someone on the online chat who said that it is not possibe to use any other label sizes even though there is a place in the multi page options to change the size of label.
I do not know the exact sizes for margins, etc for the labels you are after, but this should get you close.
I expect you to have to tweek the Width/Height/Margins a bit to make it fit.