Williams/Bally pop bumper assembly parts list:
1 pop bumper bracket - B-7417
1 yoke/stop retaining bracket - 01-1747
1 coil - AE-23-800 or AE-26-1200 (choose coil from drop-down menu)
1 spring - 10-135
1 spring – 10-7
1 plunger - 02-3406-1
1 metal yoke - 01-5492
1 fiber yoke - 01-5493
1 ring and rod assembly - A-4754
1 pop  bumper base - 03-6009-A5
1 pop bumper body - 03-7443-5
1 pop bumper skirt (choose color from drop-down menu) - 03-6035-xx
1 pop bumper cap (choose color from drop-down menu) - 03-8254-xx
1 lamp socket - 24-8776
1 pop bumper switch -  (not shown) SW-11A-37
1 pop bumper switch mounting bracket (not shown) 01-1168
3 playfield mounting screws
2 pop bumper body mounting screws
2 bumper cap screws
2 ring and rod lock nuts
2 ring and rod washers
2 yoke/stop retaining bracket mounting screws

Williams/Bally reference numbers A-9415-2 & B-9414.