heritage mosaic

I am doing a large interpretative mosaic for a local project. This is the layout for the first panel of three, I've roughly clumped the content into three ages, ancient ( this one ) , old, and modern. having enough Glass shards in nice colours will be a challenge. each panel is 61cm x 122 cm. Another challenge will be weather proofing it. On Saturday I'm doing a workshop to tie in with a biodiversity thing & will start this one off .