To just wrap this up - used the Redline website to make an inquiry late at night, quote through at 8:30am the next morning, I confirmed my address, invoice generated, payment made and confirmation of order received all within 30 minutes. Parts arrived before I'd got home from work the next day. Fantastic service.
Bolt pack ZRB05 (from the build manual) is serial number 23A - Fastener Pack - Roll over bar (DeDion FIA)