Survivor or Retro New Build?

Saw this at a little local gig yesterday, genuine period piece or a modern homage to the style? Or more likely a 70's survivor overhauled and repainted, the motor sounded really happy when it turned up and as oil tight as any pre-unit Trumpet you'll see about nowadays.

The forwards and the oil tank look raging 70's and it wouldn't be a surprise to learn that it once had 100 lbs of twisted leg springer hanging out the front in a previous life.