I got some spare sprockets and chain from
fred smoot and it was exceptionally well packed and arrived in perfect condition! He had built wooden box to fit perfectly inside a US Postal medium Priority Mail fixed-rate box (same price up to 70-lbs). Inside this wooden box, he had added additional beams to hold sprockets in place so they don't move in transit and poke their teeth through! He even labeled box with torx-bit size used to assemble to make it easy to remove!!!
Such work of art! My wife attached some hinges to box and is using it for her crafts supplies!