Yes, it's hard to be sure. Heuer made a number of models intended for timing boxing and you have to feel that these were only available to special order - I can't imagine any shop stocking these on the off-chance that a boxing referee should walk in looking to buy one. These are even more niche than the yachting models after all.

And as these would have been used professionally, rather than necessarily by someone with an interest in watches, it's quite possible that they stay with the owners, or are even discarded, rather than finding their way onto the collector's market. The owners wouldn't necessarily consider it something of value, so it could stay that way. Which would be a shame, these are interesting looking watches.

They first caught my attention earlier this year, in replying to another post that Fabrizio had also answered:

http://www.chronocentric.com/forums/heuer/index.cgi?noframes;read=27636

I'd like to think that, as Heuer went to the effort of including these in the catalogue, they must have believed there was a market for them and one that they understood quite well given they had been selling stopwatches into that market for years. So they could be out there, but in small numbers and quite possible not in the hands of "watch people". One we should keep an eye out for...