Any ideas how I go about getting the OEM lock nut? 

I just ran a search here. Turns out I'm not the first. Good advice here too to get it sorted for under a tenner ; ) 

You could go to your local LR dealer and ask them to remove the old locking nuts and then put a fresh set in. LR dealers have a full set of locking nut keys. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Even better advice is to have lockers removed, and replaced with normal wheel nuts

Why do you say that Mikey?

Where was it, in the pocket of your pants? I don't understand the connection between your pants and your lost nut? Gone - 2008 Stornoway Grey RRS 2.7 TDV6
Gone - 2009 Buckingham Blue RRS 2.7 TDV6
Gone - 2010 Alaska White RRS 5.0 V8 Aspirated
Gone - 2017 Chawton White RRS 5.0 V8 Supercharged
Current - 2010 Java Black RRS 5.0 V8 Aspirated
Current- 2024 RRS P400 SE Dynamic

He was using the word "pants" as an alternative to one of the usual expletives...but I reckon you knew that  2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Andi wrote:

Why do you say that Mikey?

Very interesting, thanks for the reply Mike.

Thanks much RRS Tdv8, I didn't because it's not an expression we use here. Pants or Strides or occasionally trousers are what you call trousers. We would just say F . Thanks, it's a new one I will use like minger (a short version of that means something else too) Gone - 2008 Stornoway Grey RRS 2.7 TDV6
Gone - 2009 Buckingham Blue RRS 2.7 TDV6
Gone - 2010 Alaska White RRS 5.0 V8 Aspirated
Gone - 2017 Chawton White RRS 5.0 V8 Supercharged
Current - 2010 Java Black RRS 5.0 V8 Aspirated
Current- 2024 RRS P400 SE Dynamic

Disco_Mikey wrote:

Andi wrote:

Why do you say that Mikey?

Because they have a nasty habit of splitting, and falling apart. All of the strength is in the outer part of the nut, which splits and falls apart.

When that happens, the softer steel is not strong enough to undo the wheel nut, and so, leaves you stranded at the side of the road...

Having read plenty of threads where locking nuts have caused problems, and only one report of wheels stolen from the hubs (that had locking nuts), I can't really see the value in such, especially given the easy availability of tools to defeat them. Rather than buy a replacement key, I'd suggest doubling the budget and buy four regular nuts.

Alloy wheels used to be relatively rare things and so were prone to being stolen. Now that almost every car produced has alloys they are probably not worth the time and effort to steal them. Especially when one considers how easy it appears to be to steal the vehicle itself with the wheels attached!

I can see how someone with pristine diamond turned 22s might be worried about theft - these are still quite popular items it seems (along with facelift lights of course). I doubt scratched 19s are much of a target (I hope, as that's what is on my RRS). 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

As above

Agree 100% with DM. Having suffered the split locker and the local tyre monkeys not putting it on and twisting the groves, and the cost of getting it sorted as PROTYRE refused to accept responsibility, I had locks removed and standard nuts fitted as didn't want to be stuck on side of motorway at night with same problem 2x TDV6. SE and HSE. Both returned to sender with issues👀
TDV8 Sport HSE...... Gone. Loved it but it didn't love me!!
Now rolling in MY10 Fullfat TDV8 Vogue. Slammed it to go round corners🙈
Cruising daily #56 mph in a Volvo V8. 😱
Lots of other toys in the cupboard...😜