I'm another one who falls into both categories Whirl. I love taking a tired old bird and applying sufficient TLC to turn her slowly into a reasonable flying machine. I love the idea of building a kit like the new Spitfire Mk 26 but deep down I know I don't have the dedication for it. Fettling old aeroplanes is enough to satisfy the engineer in me.
Fortunately those same old aeroplanes reward me with their behaviour: whether it's taming a taldragger on a narrow undulating grass strip in a gusting crosswind or sliding down from the calm evening sky in a high, sideslipping approach with an unsilenced Cirrus grumbling at tickover, just making enough noise to get the birds off the runway as you bring the tail around, straighten up and gently alight in a perfect 3 pointer (doesn't happen often I can assure you
).
Just hanging around at the airfield watching old aeroplanes potter around, talking to like minded people over a pint before going home, it's all part of the hobby called flying. Marvellous.
It was the hobby I always knew I'd have when I could afford it.