What is causing this positive camber?

The trailing arm could be bent I don't see your camber being out personally you'd have to have pictures level farther back from the car something No one's going to see camber being out by looking at any of these pictures and it depends where the camera is you talking negative camber bottom of the tire kicking out towards the curb top of the tire going in towards the body a little bit of that won't hurt much the other way wouldn't be too good shims generally not usually if it's out that bad they put it on a frame machine and they bend it literally with hydraulic rams they have a piece that fits right over the brake drum studs and they have a computer frame table or an old frame table with dial indicators and all that nonsense setup they pull on that with a RAM and it will bend it until their gauge is tell them it's where they want it then they leave it. I've had this done a couple times to Corollas generally in the front

 

In the older days of yore twas about 350 to put it on rack about 75 hrly . I've also seen people tie these things to trees with the car slightly rolling away from the tree and let the weight of the vehicle and the chain and or rope and fittings do the work pull it back towards you push it back again rock rock rock you can watch the stuff pulling of course then if the frame shop they'll try and stiffen up what they've pulled and have to know a little bit about it possibly I'm sure that today there are videos online and frame table manufacturers trying to sell stuff etc etc showing you all the tricks that used to be tricks. . Of course just before the pandemic this had been phased out years ago as it was cheaper to just replace the vehicle and move all your stuff to the new one literally I've done it like 50 times already since I was a kid all the way up through the 4 years ago was cheaper for me to go to a junkyard find a nice condition Prius that had a dent in the back that somebody had let go to LKQ was complete pretty much back before the pandemic people weren't even taking the hybrid batteries out of older Prius like generation twos they were not even on anybody's radar this didn't start going crazy till the pandemic all these cars became worth $5,000 prior to that I was paying $7,800 for a whole car running little old ladies cars parked over there at the old folk center in a few towns I go to I could get those for seven eight $900 that look brand new barely driven to the supermarket mostly sitting which is why I had to come get them because of the old ladies couldn't move them they were getting too old they didn't need to move them anymore now they take the bus with the whole crew that they keep at the old folks home the short bus looking thing van bus so all the old ladies and men could start getting rid of their cars which was the plan and I was right there to scoop them up their kids couldn't be bothered to be involved in any of that sort of thing they're such busy body people have lives etc their parents just left their cars go because nobody wanted them oh well.

 

The twist-beam is bent.

They aren't easy to un-bend.

You could theoretically shim it, but I think you're likely to be custom-making those shims. Probably easier just to swap the beam.

You can put a straight beam on a bent car for decent results. The getting it on there is what might take some yanks on the frame, if it doesn't line up at first.

Wheel bearing probably took a heck of a shot, the wheel may be drooping an extra degree or two when lifted off the ground- I'd guess it to be toast but check it either way.

 

Is a body shop out of the question? They have the tools to accurately measure the damage and unbend wrecked cars. If money is tight maybe you can get them to just straighten out the parts which keep the car going down the road in a straight line and the wheels positioned properly? I mean, you can probably live with a car which looks wrecked (bad aesthetics), but you don't want to be driving one which is wrecked functionally.