The Spitfire was a full scale fibreglass replica similar to the 'gate guardians' at many RAF bases. It was removed after the disastrous takeover of the circuit in 2007-2009 when an abortive attempt was made to host the British GP there. The circuit was basically destroyed by the bunch of idiots who leased it during this period.
The track was partly dug up and every one of its distinctive features disappeared when the track was restored a few years later:
Dunlop bridge:
Ironwork sold for scrap and the fibreglass Dunlop panels sold at auction
LINK to Chris Evans, last heard of residing in his garden. Bet that seemed like a good idea at the time!
Spark plug commentary box:
Disappeared at the same time as the Spitfire, fate unknown.
Starkey's bridge extension:
Dismantled at same time, Pirelli clock and Blue Star rocket both sold at auction
LINK and
LINK. Purchasers unknown.
As my track is set in the pre 2008 period the spark plug, Dunlop bridge and Spitfire are still in existence:
Unfortunately I don't have room for Starkey's bridge.