Ok, list of weird things that you might find in a mad scientist lab:
healthy gland
body parts
plague beast mutation core
control crystal (also you can use squirrel trapped in crystal etc)
more technical type stuff:
computers (desktop variety):
control panel and terrariums, they look really good with the bagballs green also I've seen, for specimin jars:
tinkered necklaces make ok wires, and you can get different colors that way. You could probably do a small tokuno painting, shadow dyed, then do some tinkered jewelry on top of it to look like a panel with wires coming out, and stick that in front of a stack of those golem making thingies, or just put it right on the wall.