What a timing, lost my balls as well on similar boat, similar traveler on Sunday race. Too many gybes I guess. Ordered these balls on West Marine site: https://www.westmarine.com/buy/harken--replacement-torlon-balls-25-pack--176463
Will follow the shaving cream technique from this article: https://www.chicagoyachtrigging.com/2013/09/?v=7516fd43adaa