Just wondering...this is supposed to represent Aragorn on the Pelennor Fields, which in the films he has Anduril at...

Does this Aragorn model depict him with Anduril or just his normal ranger sword? I've never actually been sure.

Honestly, I've never made a difference between the two. I would say you could use it for either one.

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Jonathan

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I've always thought of it representing him as his Ranger form, since he doesn't have his Elven dagger or Elven cloak. I'm guessing that sword isn't Anduril too, it looks a lot like the one he has on the original Fellowship model, but then again I haven't been able to compare.

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I started to walk around without shoes...

It sort of then became a Hobbit

I always thought it was his Ranger sword but all the sculpts with the ranger sword have a fair bit of detail on, but the sculpts with Anduril on (Aragorn the King sculpts) seem to have less detail on the sword, like he is in this Heroes of the West set.

Just asking cos I've got a spare Aragorn the King and was going to cut Anduril off that and transplant it onto this one.

It's different from both, actually.
Andúril has a clearly different pommel and cross guard, which you can find on the Elessar models. The ranger sword, however, is always shown with a small piece just above the crossguard (chappe?), which isn't present on the Heroes of the West version either...