Wait, they didn't buy him!

[deathproof]

I noticed yesterday Treadwell was in the Lars house - after the Jawas had one to sell that they didn't buy.

They owned that Treadwell before the droid sale. You can see him in the footage/photo helping Luke to repair a moisture vaporator while the Tantive IV is being attacked by the Star Destroyer. Luke watches the fight and then goes into Anchorhead to tell his friends, where he meets up with Biggs.