Im not a mechanic by any means so take it easy on me as I try to explain my issue below

To get the WOF I need to re-juggle and align the non-standard "helper spring" you can see in the attached pics. This spring just seems all kind of wrong to mein a lot of ways. There is no "block" or "depression" where the U-Bolt should clamp, so the U-bolt can slide down the curve of the spring as you try to tighten it. Basically the setup just doesnt look right to my eye...
You can see the stance of the car in the side view. I think the rear springs are quite "saggy" which is why the previous owner installed the "helper springs". with just 2 average size people in the back seat the wheels will rub on the rear guards at the slightest bump in the road, and the car seems to have quite a bit of "roll"
To my eye it looks like it needs to go up in the rear, or down in the front. Down in the front would be great to my eye, but I already have the front wheels rubbing on the guards under cornering and small bumps, so I think up in the back is a better/easier option. I think I might want to keep it standard also as apart from the wheels its pretty standard.
So Im thinking of throwing away the "helper" spring and someone told me you can get the springs "reset" There is a place in CHCH that does this (http://www.springs.co.nz)
My question to the gurus on here is this the best option? I would like the rear "up" just a little and probably much firmer. How would I go about communicating this to the spring guys if I just send the springs? Should I take the car to them to look at?
Should I be looking for extra or different springs from something else? etc etc
Thanks for any help guys, would like to tidy up the rear end of the old girl if I can.
Bri