Hi again, you can use this rezzer - to rez/derez a scene :
https://outworldz.com/cgi/freescripts.plx?ID=122
It's called Builders Buddy - it works for me in Opensim.
QUICK USE:
14 // - Drop this script in the Base.
15 // - Drop the "Component" Script in each building part.
16 // - Touch your Base, and choose RECORD
17 // - Take all building parts into inventory
18 // - Drag building parts from inventory into Base Prim
19 // - Touch your base and choose BUILD
20 //
21 // OTHER COMMANDS from the Touch menu
22 // - To reposition, move/rotate Base Prim choose POSITION
23 // - To lock into position (removes scripts) choose DONE
24 // - To delete building pieces: choose CLEAN