Hurro again everyone,
Further to my last, Mick Butler has kindly offered to have a look at a pic of the seat cluster to see if he can shed some light on the make of this frame.
However, if anyone else is interested I've downloaded the pix I sent him today.
Any views or ideas as to the likely builder will be gratefully received.
IanBriggs - Luton UK (sun, showers, a bit chillier today...)