I’ve now got everything soldered up and its working perfectly.
I’ve ordered my materials to be cut as well, I’ve tried to make my design as similar to yours as possible as I thought yours was so good. I’m getting the plywood, black acrylic grid and transparent acrylic front all lasered. Having followed your design, I can see some of the troubles you came up against…!
Once I’ve got all the bits back, i’ll see if it all goes together properly.
If anyone else is the UK is doing this, just for a point of reference, I bought the led matrix for £64, and all my bits are being cut for £75, so thats about $210 before you worry about the Arduino board, AC adapter, SD shield etc etc…