there are some topics on using Jumper-Wires, example: https://pinside.com/pinball/forum/topic/using-schematics-and-8-foot-jumper-wires
The JPG here I made from ipdb-schema "Williams Space Mission". Lets say the 10 cent relay does not fire. Maybe there is a fault-A in the connection "Power-Side" (a wire has broken-off somewhere) --- but there is also a fault-B in the connection "Returning-Side back to transformer" (a switch does faulty not close).
If I do jumpering on the Power-Side-Connection: fault-B hinders the relay to fire.
I then may say "OK - I try the other side" - I do jumpering (only) on the Returning-Side: fault-A hinders the relay to fire - thats why I have written in "blue": Set a Jumper on the Power-Side and leave it there (IMPORTANT: When the schema shows permanent connection !!!).
The schema http://mirror2.ipdb.org/files/232/Williams_1975_Big_Ben_Schematic_Diagram_paginated.pdf on page-1 tells us: "Good side of '24 Volt-15-Amp-Fuse' to use has soldered-on: Wire-Black"
It also tells us "Good side on Transformer-Returning-Side has soldered-on: Wire-Yellow" (actually there are TWO Wire-Yellow soldered-on).
I look at Your picture (post-18) - the pesky Double-Bonus-Relay --- on top of the picture I see a bare / naked wire. Follow in Your pin this bare wire --- You will come to the coil of another relay and there is soldered-on: Wire-Red. I look in the schema on page-4 and see: Wire-Red, then Switch on Tilt-Relay, then Wire-Red-Yellow-White, then Switch on Reset-Relay, then Wire-Blue-Yellow-White, then Switch on Game-Over-Relay, THEN Wire-Black.
I prepare the "Jumpering the Power-Side": I unplug the main power cord (Safety Reasons), I clip-on a Jumper-Wire at the Coil on Duble-Bonus-Relay, side "Bare-Wire is soldered-on". I run the Jumper-Wire NEAR the socket on the 24-Volt-15-Amp-Fuse - and lay the Jumper-Wire-Gator-Clip NEAR the socket (NOT touching a thing).
I plug-in, toggle-on, start a game, after the pin has resetted: I clip-on the Gator-Clip at Fuse-Holder-Socket "Wire-Black is soldered-on". I then make some points - I then press the armature / anchor-plate on Double-Bonus-Relay and let go - question: Does the relay keeps-on pulling ?
IF (if) "No": (I let that first Jumper-Wire as is) - I take another Jumper-Wire and clip-on at the "Coil on Double-Bonus-Relay, the other side (NOT: bare-wire-side). With the other end of this Jumper-Wire I touch "transformer-Lug-Yellow - question: Does the relay fires ?
If "No": Coil is bad. If "Yes": Want to try (?): Take away the first Jumper-Wire and do the test ONLY using the second Jumper-Wire - question: Does the relay (still) fires ? If "Yes": No need to use first Jumper-Wire anymore. If "No": At least one fault to fix on "power-Side-Connection".
Look at the JPG --- You have done "blue jumpering" and "burgundy-red-violet '1S' jumpering".
Please write about the results of Your tests. Greetings Rolf
P.S.: Sometimes I use Jumper-Wires (I want to see "action" on relays / stepper-units) --- sometimes I use a test-light (I want to find out "is there power in between point-A and point-B"). Here: https://pinside.com/pinball/forum/topic/reading-gottlieb-schematics --- SteveFury shows in post-12 his "Test-Light" (good for Williams and Gottlieb pins as they run on 24 VAC).