Yeah I thought it'd be like any other custome gear and the item would change to the level of the armouring/Barrel you put in but droid pieces stay at the level they are it seems.
Actually gear that is level 44 (for example) will remain level 44 even if you put low level mods in it. Found this out the hard way as my jedi friend wanted trooper gear and I just happened to have some oranges he liked laying around. Sent them to him and he removed all the mods since they were about 20 levels too high for him (and for troopers) and put in new ones. Couldn't put on the gear as it still said it was for level 44 only.