3 pages and no-one has really helped the guy?
If you want to change the shifting to bar end levers (often referred to as 'bar-cons) you'll need to take those terrible plastic shifters off and replace them with these:http://www.ebay.co.uk/itm/Campagnolo-Do ... 4ac998fb5e
This turns the shifter mounts into cable stops with a barrel adjuster.
Then you'll need the shifters. These mount inside the end of the bars but prices seem to have gone sky high due to the time trial connection (?). 7spd should work ok if you can find some, 8spd may work but the spacing is a little narrower on the shifting.
Your cassette/ freewheel is not ramped for shifting but this doesnt matter too much - BUT, you will need to change that rear mech. Good indexed shifting needs a Shimano 'slant parallelogram rear mech'. Just about any road/ mtb mech from the mid 80's onwards will work. These are often cheaper in comparison to the shifters.
a 'retro' example:
You might want to change your chain as well. From memory, that particular Sprint used to come with a big old 6spd chain. A later narrow chain such as a nice chrome KMC would shift better as they are chamfered to aid shifting.http://www.ebay.co.uk/itm/KMC-Z82-Silve ... 46139745d1
Hope this helps...