FINNEY1973
Senior Retro Guru
I think an older frame with a new groupset can be done tastefully. I've long admired the bikes that Feather produce and I know it isn't an old frame, but it is retro styled and constructed properly and then adorned with modern stuff...anyway have a gander at the bottom of the link for a bit of inspiration...
http://www.rapha.cc/ricky-feather?locale=UK
http://www.rapha.cc/ricky-feather?locale=UK