Vibra~Plex makes an "Old Schoolish" looking signal kit..(looks sorta like the ones on the 50 's Ford Truck and some cars..) A little chrome box that mounts on the column and has a Green arrow for left and right Indicator ON it..
I Don't know of any place that actually sells the unit..Do a Goggle on Vibra~Plex, and maybe even a Evilbay or Craig's list (for N.O.S. or used working)
You MAY find a copy at Auto Zombie as a "Generic" System kit..
Either is Simple and easy to install and looks about as old school as your gonna find I think..
I think those little lamps are parkers..but CAN be wired For Signals as well..
You Will also need to encroach on the Brake-lamp on the rear and the Brake lamp switch to install. If your stock, you have only one Brake / Tail lamp Right? Or was an after market Right Lamp installed also?
My question here would be, what Steering column do you have? Stock or late Model GM type?
Congrats on your New acquisition!