Thanks for that Sancti, though I already have that Tweedie Genealogy site with its info from the very thorough 'The History of Peeblesshire' by J. W. Buchan and Rev. H. Paton. Published 1925-7..
What I don't have is whatever is in that 'Publications' from the Scottish Record Society (1932), though it may, for all I know, simply replicate what you've just posted below.
I also can't find out that much about this particular line of Andersons beyond the Michael who bought Tushielaw from a Walter Scott in 1688.
Brian