Thanks Kong for the report.
There are 3 theories for the '68' numbering.on the tee-shirts.
1) It is one numeral less than '69', which is another popular lucky number for some brands' limited edition watches.
2) In 1968, IWC started a special training unit for their high end watchmakers.
3) F.A. Jones founded IWC in 1868 and lost it by 1880.
hmmmm.....Lets vote for our favourite theory!
Regards,
MTF