IIRC the nose at Duxford is an original MkII , as are nearly all original Horsa cockpits, the only original MkI Horsa nose is at Middle Wallop. The last time I visited the AGT at Shawbury there was a veritable cockpit production line with a number being assembled alongside the completed Horsa fuselage, which is why I’m wondering where they all went.
There is another Horsa Mk I cockpit being built by Jet Heritage at Staverton, but this is independent of the AGT production.