Hi John,
well I have a couple of take up spools like yours in my Kievs, and after examining the situation I decided to trim the leader and use it that way without problems. Curiously, the Feds-Zorkis all have a "normal" take up spool...
Another option would be to fold it, I suppose, but you can also build your own easy to load spool, this is a link to the how-to, part of the website of another member of this forum, ZeissFan.
http://host.fptoday.com/melek/zeiss/repair/spool.html
Best !
Oscar