Ok, so something of an image bomb, explaining how I made the minifig frames.
Requires:
Ribba 23x23 cm^2 Frame (white)
thickish white cardboard >23x23 cm^2
Prittstick glue
cutter
superglue
A bunch of old LEGO
16 white inverted 2x2 slopes
Step 1:
Take apart the frame and use the pritt stick to glue the cardboard to the back wood panel.
Step 2:
Cut out the white cardboard along the sides, paying attention not to cut to much away from the "missing corner".
Step 3:
Use your (preferably) old lego to build a frame as follows, the dimensions are chosen to create a perfect fit for a minifig series of 16 minifigs. Add flat tile plates to the openings to accommodate smooth brick entry.
Step 4:
Align the lego frame with the bottom of the white back plane and horizontally centre it as well as possible.
Step 5:
Prepare the inverted slopes with a flat tile on top and get the superglue ready.
Step 6:
Add a small drop of superglue to the back of the inverted slope and carefully insert it into the ready made holes, be sure not to use to much glue or you risk gluing your whole structure to the paper. Less is more!
Step 7:
Due to the limited amount of glue used in step 6 some of the slopes might not stick to the background after removing the LEGO scaffolding. These can then be added one by one by using a small scaffolding (shown left) using the stuck slopes as reference.
Step 8:
All slopes should now be securely fastned and the flat tiles removed, position and distribute the minifigs as you desire.
