Hi Mike,
My spring compressors are like the ones Ron shows, the only mod I've done is to grind away part of the hooks because they were too thick as standard to go between the coils of the springs I have. What I normally do is to leave the top & bottom coils free and place the hooks on maybe the 2nd/3rd coil from the end. Then compress until coil-bound, very slowly and usually with my foot on the spring at the time (assuming it's off the car
) because I did have the compressors slip once and a spring bouncing around the workshop makes deep dints in whatever it hits !
Then I use plain rope to hold everything in place, as much a safety measure as anything. I wouldn't use tie wraps because being plastic they can go without warning and you're back dodging wild springs. Flat rope is hard to tie a knot in, and maybe that's the problem you have ? If not plain rope then I'd use the nylon straps with steel adjusters that you use for holding cars on trailers, I forget what they're called but you know what I mean ?
Don't beat yourself up about that installation though, the springs you have look as if they will be quite a tight fit on those dampers and I'd also struggle with getting them on. The only thing I can think of with your compressor is to cut the top plate so that it's a "U" and can pass over the largest fixed washer on the top of the damper, then slide it between the 2nd coil down and go from there. Tight engineering though, there doesn't look to be a lot of room to play with ?
Brian