In SKetchup regulated in unities that you want: say (cm 3D)
Import the Moi object (created in any unites)
Select All
Make group
Take the Tape Measure
Measure (with 2 clicks) one edge of anything that you know the size must be (say 5 cm if SKetchup is regulated in cm):
12.7000 cm is realy measured on the edge
Enter 5
"Do you want resize the model?" Yes
Explode the group
That all!
You will have all thing you want even something is not yet resolved in Moi :)