The Christmas sleigh was designed such that you do not need any glue to assemble.
The reindeer design was designed such that the joints should be tight-fitting. However, you may need a bit of tweaking if your acrylic sheet is not exactly 3mm. Or, you could always use a bit of glue.
Have fun building an "army" of reindeer to pull the Christmas sleigh!
P.S. Anyone wants to contribute a Santa Claus thing to man the sleigh? :p
The XMAS Tree can be found here:
Or if you prefer a ball-shaped Ornament: