I recently saw this picture from a family in Spain (Instagram @johnnyguitarrinchi) who built a model of the Ark of the Covenant. It looks like they used a box, some gold wrapping paper and made some cardboard cut-outs for the angels. Very creative!. This looks like a fun and easy project for a family. While it does not show the contents, I suspect they also made some things to represent the various items contained inside the ark. This could be nicely incorporated into a discussion of Chapter 25, A Tabernacle for Worship, in the book Lessons You Can Learn From the Bible.