IIRC,225 X 38MM Scaffold boards are mainly western white spruce, stress graded and end banded showing the bs number for a usable board, which would be a grade "A"
THERE ARE 65MM scaffold boards, but not for £14.00!
There are 225 xMM scaffold boards available, I hear, that have failed the BS stress grading and are sold, off cheaper.
Should you be a scaffold furniture builder, these are sold, I believe, without the end banding,
And what you would be after.
I would Google reject scaffold boards, or some similar title, and see what may appear.
HTH, Regards Rodders