Looks good Ben.
Couple of things, wouldn't be a bad idea to run some split ribbed flexi conduit round some of those smaller wires to give a bit of protection from chafing. The cross link cable even has it on the 80 but that cable has very tough insulation so it may not be necessary for that. The smaller wires coming from the + terminal in pic 2 would be better coming from ring terminals from the clamp bolt rather than the ones gripping the cable in the clamp tube, better still, there are small fuse boxes available that could be fed with one short larger cable. The main thing is that any cable smaller than the starter cable needs to be fused or fitted with a fusible link as close to the battery as possible. Lots of cars now have them fitted to the battery post clamp itself.