Crompton "Trueflame A" 40w amber GLS lamp (with Belling branding)

Pilfered out of an old Belling heater (a "Champion" 91A model) I am currently repairing/restoring in readiness for use this winter. This appears to be the heater's original lamp; I wasn't aware Crompton ever went as far as specifically branding lamps for Belling. Unfortunately, as one might expect, it has probably long-since reached EOL. I'd be interested to know what the "Trueflame B" looked like. Presumably it was just a standard lacquered Fireglow lamp.