If you can find some .010 and .020 copper shear wire, that might do the trick. Safety wire/Lock wire is probably too stiff to work with. Also you might want to find some small guage solder. That stuff is very maleable and does a pretty respectable jobe in replicating rigid hydraulic lines.For the electrical harnesses (depending on how small a diameter they are) you could use some fine guitar strings (I don't know a thing about guitars but I know some sizes of string make excellent oxygen hoses in 1/48th), short of that, All I can think of is using small guage wire with some thread wrapped tightly around it to replicate the look of an electrical harness.
HTH
I knew there was a good reason I picked 6112 as an MOS!
Jonathan Primm