The TSA guide says that "Realistic Replicas of Explosives" are not allowed, and yours kind of qualifies. Of course it lacks a critical component, namely an accelerant and/or explosive, but good luck convincing airport authorities anywhere in the world.
The best thing that comes to mind is to disassemble partly the components, particularly the analog ones -- keypad and cabling, mostly (hopefully not everything is soldered) and pack them separately. The rest would look much more like a harmless circuit board, and you can transport those without anyone making a fuss about it (I've done this previously with various hardware components both in my checked and hand baggage).
If that's not possible, then you should contact the airport security in advance and explain your situation. If you are forward about it with and show them and explain what you are carrying, you should be fine. Security personnel would probably want to look at it with bare eyes, so make sure it's easily unpackable.
Got a somewhat related anecdote as well: some 20 years ago, my mother travelled from Moscow on a business visit and had bought me a toy -- a fairly large moon lander, equipped with faux antennas, lamps, and "remote" controls with cables. She packed without much thinking in her handbaggage, but without the box. At the security scan at the airport, the security personnel became visibly agitated and reached for their guns until my scared to death mother showed them what the bulky box with doubly suspicious antennas and cables really was.