This plastic version of an Altekruse 12pc puzzle made by Skor-Mor is probably the only one this fancylooking . There are probably several ways to assemble this one, and this page depicts one way to do so .
The Blue Core
Take the four blue pieces and form the 'core' of the assembly.
Two double pieces
Form two cross pieces (red and yellow each) . . . . .
~ and place one in front of . . . and one in back of ~
the 'blue core' .
note the orientation of the notches of both yellow pcs and red pcs
now temorarily remove the 'blue core' for the time being . . . . .
Add the 'Bottom' Yellow . . . . .
~ in the exact center ~
Add the 'Blue Core'
Add the 'Top' Yellow
Add a single 'top' yellow piece. You will have to slightly lift up the 'blue core'
~ and maneuver it slightly sideways to the right ~
to allow for the insertion of the top yellow piece,
then settle the 'blue core' down again so that its again flush with the rest of the structure.
Last 2 red pieces
(These next two pics below only show the orientation of the notches before entering into the actual puzzle structure . . . as in the 3rd picture below left).
the right-hand pic above does not represent the actual structure--in--progress thus far
\/ actual puzzle structure \/
Add the last 2 red pieces . . . . .
(one on each side of the structure)
onto the other red pieces already situated in the puzzle, by slightly lifting the 'blue core' just enough to allow those red pieces to fit in exactly the same orientation as depicted above .