We wanted the look of vintage line on a few of our boats, so we did some research with our friends at R&W Rope and found New England Rope Vintage and New England Rope Vintage Sta-Set. They come in small enough diameters for our small boat rigging.
They also sell a tan paracord that worked nice for whipping and bending sails onto spars, and natural hemp in very small diameter, good for brailing line.
R&W Rope
NER Vintage Jamestown Distributors