LO, you are right, just some rescribing for the rudder balance and a different colour scheme would be the major differences. If I had the space, I'd do a whole lineup of Spitfires/Seafires*. I want to do an early Spitfire from 19 Squadron, possibly the first Spitfire to be written off, the serial number of which escapes me at the moment as most of my references are in storage.
And yes, instruction sheets used to be much more informative about "the gubbins" than they are now.
* Disclaimer, my favourite piston engine aircraft is the Mosquito, my favourite jet is the Phantom, not that anyone cares, I suppose.