Look for an ogee skirting. How much do you need, though? If it's only a little you may be able to pinch some from elsewhere, say a cupboard, use that and then replace thecstuff in the cupboard it with a near match. It will be less noticeable in that position
If you can trace around it, you might find some have the top bit cut off which you can see, of you search for ogee skirting some places come up some in MDF some in pine but its investigating which is the one for you.
A small joinery with a spindle moulder might or might not be able to do it in sections.