[QUOTE=markxsherman;13256306]I may have access to a 1984 Mercian frame that was bought new and never built up. I don't know the model but it was supposed to be their version of a road bike (not competition).

Is it better to build a bike using a 1984 Mercian frame or would it be better to buy a new bike with? That is, has bike technology made the Mercian of the 1980 obsolete?/QUOTE]

I'm not sure what your are asking. Are you asking whether to build up the Mercian with new or old parts - or are you asking whether to build up the Mercian or get a new(er) bike?
If you are asking whether to get a new(er) bike, then I'd say do it because you are not enthusiastic about a NOS 1984 Mercian - and there can't be very many of those around. No sense decreasing that number if it's not something you particularly want. On the other hand, if you are enthusiastic about it, then I wouldn't worry too much about authenticity (though I think it would look better and work well with period correct components such as those recommended by rekmeyata). Personally, I'd be reluctant to do anything to the frame, such as spreading the rear triangle to accomodate newer wider hubs.