Ray Dobbins made mention of this brake set: but it is interesting.
eBay item number 260003062649. Link:
Very nice overall presentation, the high price just makes me wary of trying to recreate a 1968 Italian professional level bike.
The special Campagnolo marked O ring replacement on the front adjuster looks to me like a pump washer for sealing the pump to the pump end fitting.
John Jorgensen
Palos Verdes Ca