The difference between the R1155L (and N) and other models is thankfully limited to the Coil-Box. L6, L11 and L18 are replaced with L40, L41 and L42. Refer to chapter 35 in A.P.2548A for a detailed description of the changes. A rat’s nest at the best of times, this one was no exception. Judging by the nature of the wiring, I have to conclude that someone had been there before me and replaced the old rubber or cloth covered solid core stuff with brightly coloured PVC-covered multi-strand wire. This may be have been carried out in 1958. There is a service label on the front panel with two entries dated 1958. My task was to carefully dismantle each section in the Coil-Box,  keeping careful note of the wiring, whilst comparing it with the circuit diagram and then drawing the wiring routing along the lines of that shown in Peter Holtham’s book.  

Restoring R1155L Ser. 0138 page 2

The vitreous enamelled resistor (right) between the 9-way tag board and the bias tag-board was initially thought to be a ‘new’ addition but turned out to be repair, replacing R3 on the bias board.

Most of the 1940s vintage resistors had been replaced as the photograph on the left shows … five different styles in the area of the second IF amplifier alone!

Like in the DF circuit, some of the 0.1uF capacitors had been replaced.