I have recently fitted a Bartels spar. I contacted Brigitte Zettler-Kufner: firstname.lastname@example.org and just asked for a ‘wayfarer genoa reefing system’ and she supplied a quote with a list of part numbers.
They do have a cataloge on-line, and I extracted a few pictures to provide info for making a new genoa. There are several parts in the Bartells quote, but you can find the sketch that Bartells provided, togther with some notes & pictures of the asspciated parts at:
(If you can’t get this, I’ll email it to you privately if you send me your address – I don’t know how to attach pdfs to this forum)
By the way, I’m very pleased with the spar, but yes, it did take a stiff drink.