It it is from a signal lamp possibly an Adlake but would suit others. It will slot into a standard 24.5 mm aperture in your reservoir - adjuster shaft approx 35mm to the burner centre, stamped British make & Sherwood Bham to the adjuster knob.
BR RAILWAY SHERWOOD SUPERLITE BRASS & STEEL SIGNAL LAMP BURNER SUIT ADLAKE 1950
Vintage Original British Railway Lamp Vaporite BR/WR Sherwood Bahm Burner
BR RAILWAY LAMP SHERWOOD BURNER & RESERVOIR 69 MM x 140mm TALL SHAFT 20mm WIDE
BR RAILWAY HAND LAMP SHERWOOD CERAMIC BRASS BURNER 70MM SHAFT STANDARD FIT
BR RAILWAY LAMP SHERWOOD LYNLIGHT BRASS BURNER & WICK 80MM SHAFT
