Hey Stu,
Not sure if this helps or not but to crack the ones on my buggy loose I took it over to Kal Tire by my house while it was on the trailer and they had to hit it with the largest impact wrench they had to break them loose...
But I guess the car might be in pieces at the shop...if you want to borrow the trailer you're more than welcome, just let me know and I'll pull the lock off it.
Maybe a local shop will let you borrow one? Better yet hopefully someone on here has a torque master you can use...
Ed