If the new switch does not have an instruction sheet showing a mod, and the numbers tally it should be ok to change lead for lead, number for number. Nos are usually P1 and P2 mains, 2 and 4 loads, s1 and s2 neon lamp, or pilot neon lamp. Before switching on we would check the resistance at the input t/block with mains off, Probable readings 50ohms/24ohms if zero ohms do not switch on it will be a dead short (BANG!)
Kenjo, August 2014