Help with part numbers, please

Hiya - back here after an 18 month lay-off and about to get my knuckles skinned again - oh the joy.
Anyway, my 110 Defender is a bit of a hybrid, with bits sourced from all ages which the PO didn't keep any records of. I need to replace the rear brake discs but he swapped the Salisbury axle for a "Rover axle" - by which I assume he meant a Disco. I've searched all over the usual places for a serial number on the axle but there's so much POR15 on it, it's invisible, so no idea how old it is etc. Question is - what's the part number for new brake discs, pads, drive flanges, flange bolts etc to overhaul all this? Are the options simple or do I have to pull everything apart to find out? What I do know is the half-shafts are 24 spline.
The wipers won't switch off. I disconnected a wire at the steering binnacle that allows me to get them to come on at normal and double speed, but no intermittent wipe and no auto-park. I assume that this is a faulty park switch (LR057182G) and I believe the wiper motor is the original fitting (1995 Defender utility).
Anyone advise, please?

Search here for all part #'s https://www.lrworkshop.com/diagrams/land-rover-defender-braking-systems/calipers-drums-discs & https://www.lrworkshop.com/diagrams/land-rover-defender-axles-suspension

Complete simple fault finding exercise for wiper issue. Start with inspection and properly testing the wiper looms wires, for both continuity and load. Aged wires will often ready 0ohm [good] but breakdown under load :. high resistance = not enough current + risk of wire burnout/fire. Then, if fully operational once intermittent relay replaced/correctly working + wipers correctly working...the fault is within the wiper switch function. Once fault found it's really worth cleaning up all terminals [lightly with 1200 wetted with WD40] and re-securing/tightening existing crimps.