I've used magnetic drain plugs on my motorcycles and prius, and so I wanted to find one for the Disco II. I couldn't find a spec for the threads anywhere, so here you go! Autozone for $3 as opposed to the LR non-magnetic $12 I had to buy to find the spec and suitable match.

Thread: M14-1.5
Autozone Part # 652166

Here's the drain bolts in their packages:


Here's the drain bolts out of their packages, compared:


I'm changing my oil as soon as I get a non-snowy/rainy day. I'll update with photos of it in the oil pan.

 

Nice find and thanks for the part #
I had one of those on my VW and liked it.
On my work truck I put a fumoto quick drain and really like that too. Turns out it's the same thread and pitch. A little pricier then yours. But I think it's worth it.