How to buy individual LEGO parts, pieces and Minifigures?
Hard-to-Find LEGO Colors (and what to do about it) - BRICK ARCHITECT
Gobricks GDS-872 Window 1 x 2 x 2 2/3 with Rounded Top compatible with lego 30044 All Major Brick Brands Toys Building Blocks Technical Parts Assembles DIY (194 Light Bluish Gray(071),20 PCS)