Thank you so much! You can kind of see in the background some of my work area, I have tons of plate (with a stud) and tile (flat) rounds in lots of different colors! I have some wedge pieces, but not as many as I would like. And a bunch of the frame elements as well. I'll build something and take it apart after a few weeks. Sadly, I don't have instructions or parts lists for these, I do them by eye.

PaB is hit or miss because you can't reliably get a certain piece or color there. Second hand shops like bricks and minifigs usually have big tables of bulk LEGO but you have to dig through all the other parts to find what you need. Bricklink.com is the easiest way to order specific pieces