Hello Moto,
Congrats on getting in!
In terms of scholarships, Oxford is slightly thrifty. There are no blanket bursaries they make, all are based on income. Unfortunately, I have no experience of these.
The physics department also give out bursaries. I seem to remember they only released the terms and conditions to qualify for them about a week before I "came up", so don't be surprised if they do the same for you. If you email me on the address in my profile, I'll try and forward their email to you so you'll be ahead of the game.
As for companies giving scholarships, well, that depends. If you're willing to sign your life away, I expect quite a few firms would be happy to pay your way through uni so that they have a fully qualified physicist at the end of it. I seem to remember the Army are happy to do that. I'm afraid I don't know any more than that.
If you have any more questions about Oxford or Mansfield, don't hesitate to get in touch.