Dear Alistair and Richard,
Thanks Alistair, if you do have one I would be most interested.
Richard, I think I have found an image of the Gypsy heater, which other than the fan motor which sticks out is appears to be slimmer than the Clayton or smiths version. If you have the heater handy, would you be kind enough to measure and perhaps post a photo please. Where did you source the heater?
Regards to everyone for the invaluable help
Jack
Jack Peppiatt