just thought - to double check you could swap the front wheels to the rear to see if this makes a difference

that would only prove balance problems though yes? Discovery 4 HSE
1998 110 TUM HS FFR Hard Top XD WOLF
1982 Series 3 Hard Top

*Gone:L462 D5 HSE LUX, L663 Defender 110 HSE, Discovery 3 HSE, 2014MY Range Rover Sport 5.0 Supercharged AB Dynamic; L405 Exec Vogue SE 4.4, 5.0 Supercharged Autobiography, Defender TDCi XS CSW, Defender TD5 HT, Vogue SE TDV8, Vogue TD6, RRSport SC 4.2V8, Classic 3.9 Vogue Auto, Land Rover Series 3 SWB

If it still wobbles then its the discs. If it doesn't wobble anymore then its the wheels - either way you should know one way or the other - Worked with one of my vehicles. My guess though is that if it only occurs when you touch the brakes its got to be a disc, otherwise the vibration would be there all the time.

Just a quick thought, If you have towed something very very heavy and used the brakes excessively this can warp a brake disc - usually on the front. I also know someone who had very rusty discs and drove a car for a couple of miles with the brakes lightly on to try to clesan up the discs - result was a badly warped disc...

RRUK Shame you arn't down my way

indeed! Discovery 4 HSE
1998 110 TUM HS FFR Hard Top XD WOLF
1982 Series 3 Hard Top

*Gone:L462 D5 HSE LUX, L663 Defender 110 HSE, Discovery 3 HSE, 2014MY Range Rover Sport 5.0 Supercharged AB Dynamic; L405 Exec Vogue SE 4.4, 5.0 Supercharged Autobiography, Defender TDCi XS CSW, Defender TD5 HT, Vogue SE TDV8, Vogue TD6, RRSport SC 4.2V8, Classic 3.9 Vogue Auto, Land Rover Series 3 SWB