I have undertaken a quick piece of research!
Although it is well known that the Battersea Big Dipper used ex-Margate trains, I have several photos of the ride in operation (date unknown) and the trains are very different from those on the Scenic. They don't have dragons heads - they have curved fronts. So that is a mystery in itself.
The Scenic Railway at Belle Vue did have dragons heads identical to the ones you have acquired. There is a picture on page 62 of 'Roller Coasters: Shake Rattle and Roll' (
http://www.joylandbooks.com/books_new/coastersshake.htm ) and on the front cover of 'Looking Back at Belle Vue' (the cover picture is here:
http://www.joylandbooks.com/books_new/l ... llevue.htm ). In the book 'Roller Coasters: Their Amazing History', there is even a close- up of the brakeman's seat, showing that there were also dragons heads next to that as on Dreamland's scenic, but they were slightly different to the ones on the front (less 'ornate' at the bottom).
The Scenic Railway at the Franco-British Exhibition also had identical dragons heads.
The Barry Island Scenic Railway didn't appear to have dragons heads, but that was a later and very different Scenic.
I am sure I have several more photos hidden away somewhere.
It seems like the 'first generation' scenics all had dragons heads. How many of the later ones did, I cannot say. It therefore seems likely that several scenic railways would have had similar dragons heads.
Yours might have come from the Belle Vue Scenic which was only demolished in the 1970s.
Nick