Wood border

Looked at a really nice job last week that needs sanding and finishing and another 30 m2 made up to match. Not something I've done a lot of and was looking for some input/advice on the best way to match it. I can't make out or see if this is 15mm block or 10mm overlay but it's been pinned on the borders and is solid subfloor

 

Well thank god Mattys on the bwfa apprenticeship....he's told me how to make up the border lol.