Yagon,
Here are a few links you might find helpful. They are Parallelograms that can be made at home from different materials.
http://home.wanadoo.nl/jhm.vangastel...ocs/binocs.htm
http://www.gcw.org.uk/bino/binonet.htm
http://members.aol.com/scottw8088/binoc.html
http://www.astro-tom.com/projects/binocular_mount.htm
and there are lots more to google.
I hope that helps a bit.