Shimano made 7-speed bar-ends (I have a pair on my touring/commuting bike). However, the Dura-ace rear derailer and shifter of that era is not compatible with any other Shimano and I'm not sure that Shimano ever made Dura-ace 7-speed bar-ends. I've certainly never seen any.
But, 7-speed spacing is very close to 8-speed (5.0mm vs 4.8mm) and I have friends that have used 8-speed shifters for 7-speed drivetrains. So you could try using a pair of 8-speed Dura-ace bar-ends. And because of the changes made when Dura-ace went to 9-speed, all Shimano 9-speed shifters will shift a 7400 series rear derailer for 8-speed spacing so you could get 9-speed bar-ends, too. I have these on my triathlon bike and there is a sticker on them that says "compatible with 8s (7400) and 9s (7700)" or something like that.
Another thing you could do is look at converting down-tube shifters to bar-end with something like this
http://www.rivbike.com/webalog/shift...urs/17068.html