Another one of my Alternate Spitfire lineup, this is a the prototype low back, modified from an Airfix Vb with a home cast spine (I've since revised themould to something far better).
Other mods included removing the crude Airfix interior and replacing it with some home cast resin bits. The canopy is from the Airkit Spitfire F22.
hmm very interesting. cast spine you say? impressive
I cloned the low back from the Fujimi FR.XIVe but the original mould left too much to clean up. That's what I used on this one. And plenty of filler too...
The rubber I'm using now is more flexible, meaning finer detail. The new part is a closer copy apart from a web of plastic card to enable the air to evacuate as I dripfeed the resin in. I still haven't used any of the newer parts.