The Southern Railway introduced this style of signal bracket in the 1930s, to fit its economical rail-built signal posts. It was never used with any other style of base post. Dolls were always of the lattice pattern in SR days, but a very few tubular dolls may have been installed in the 1960s by BR(S). Some are still in use today.
This pack contains bracket and landing components only. For a complete signal, you will need: a rail-built base post (scratch built); dolls (SN22); signal arms (SN12/2); finials (scratch built); lamps (SCN6); and ladders (SN9 series).
The actual size of the fret is 36½ x 17½mm; it is etched in 0.008″ brass.