Be warned Rabbit Leader.
Isaacs designed two replicas, the Spitfire and the Fury; I understand that the man-hours and manufacturing techniques are pretty similar between the two.
I met a gent once who had just finished building an Isaacs Fury, which he'd started just after he'd retired. I asked how many hours it took, he said about 3,500.
What profession had he retired from? - he had spent his entire life as a carpenter.
G