In a similar vein to :
If you could reintroduce into service an upgraded new build of a proven design.
My vote would go for 'best machine the RAF never had' goes to the Viggen.
In the early 70s we could have been buying Viggens in the place of:
Harriers, Jaguars, and perhaps some F4s, while replacing Lightnings.
Looks good in RAF markings I think
