I need to fill in a 17mm x 16 mm rebate in hardwood ("canadian
doorstock") door made for a previous water bar.

Once upon a time a piece of ramin beading would have been ideal, but
ramin is no longer sold or imported (protected species, SFAIUI) & all
beading sections in places such B&Q & Homebase are in softwood.

I am reluctant to use softwood as at the foot of the door I sense it
is likely to soak up water & thus not last.

Any suggestions as to a ramin alternative (and source) please?

TIA