is the bike some sort of old classic? if not, consider just renovating using current components. modern shimano/campag/sram integrated brake/gear levers are a far better experience than an old bike with suicide brake levers and down tube shifters.
i have a 1951 claud butler bike that i would not dream of putting anything modern on (it's a fixie anyway), and an 80s raleigh frame that has been done up with modern components, as it's no classic. the bike will be much nicer to live with done up modern, but it will cost you more than it's worth.
if you're wanting a real project, pick a classic old 531 racer that was made by a classic frame builder.
edit: elswick was a good name back in the day, but the names of all but a few of the classic builders became little more than brands to be sold on. for example, pre '57 all claud butler bikes were made by the man himself at his own premises. he went bankrupt and the name has been on bikes of varying quality ever since, with the 80s probably one of the worst (they seem ok entry level bikes these days).
