No I dont have specs - just made them to suit.
The top ring is 1mm thicker than the height of the lip on the top of the strut tower
(I think about 8mm) with a chamfer on the inside to suit the radius of the lip
The bottom ring under the trut tower I made about 6mm ( diameter to suit , holes to suit )
Sorry I had no need for a drawing

The adjustment rings below the spring should only be wound down ( can only be done with the
car jacked up and most of the pressure off the spring ) until just before the spring becomes loose ,
this is the lowest you can go without the springs becoming uncaptive on full droop
If you want to go lower without this downside you could
1) possibly get longer helper springs ???
2) reset the position of the strut top mount ( as above )
3) fit shorter strut inserts ( shorter on extension )
4) Ask the brains trut here :)