Haha, well looks like you've maybe found a solution, but I've concocted a plan B if that doesnt pan out.
Your problem is that the celica has the steering arm cast into the hub, one piece, and you need the steering arm lower down, relative to the centreline of the wheel bearings.
80s RWD struts have the steering arm seperate, the strut sits on top of the steering arm, and the hub bolts to the strut.
So the steering arm is lower down for starters, AND when you use RCAs, it lowers the steering arm even more, relative to the centreline of the wheel bearings/hub.
I'd go have a look at GX71 cressida struts/steering arms, and see if you get lucky and they bolt to your lower control arms.
Work out what length RCAs you'd need to space the steering arm down far enough to work as you need it to, and buy some in that size.
Steering arms are out the back in this instance, but you could possibly run them backwards, but swapped left to right so your ackerman stays about right? (dont quote me on that)
Here's an awesome diagram.
