i dont think its as bad as it looks, i would sort it out, try to figure out where the connectors should go (cluster, switches, steering column, a/c), maybe tie the harness back together some, did you get the car like that or did you take the dash out, what parts do you have? i work on mercedes and after you get the carpet out and open the harness on some cars its crazy, figure some benzs have 100 control units that all need to talk to each other, your best bet is to dive in and see whats what and what your working with,
have fun and good luck