OK ... let's start broadly... sequential turn signals are where , instead of flashing a single or double lamp light in the usual on/off state, there are three lamps in a row and they light one two three in a sequence going outwards, there is no off-state.

OK... now let's narrow the focus.

This sequential idea (very USA) is relatively easy to do as indicators-only with  a solid-state circuit.  However it is much harder with sixties electro-mechanicals, where only relays and cams and mechanical sequencers were available.

Narrowing that focus even further... what makes this REALLY difficult is the USA law (and I believe it is still allowed today!!!!!) that allowed using just red lights to multi-purpose for indicators and brakes and parks.  

Now, we not only have electro-mechanical complexity... we also have a triple sequence for red indicators...AND an overide for brakes.  The system has to allow for directions, sequencing of 3 red indicator lamps, and allowing brakes to OVERIDE those same three lamps for a brake-blast of three lamps.

The video shown here shows a set of these working in the USA by the sound of the voice. I found this video on youtube.  It is not this set.  This set is straight off a working car with the instructions too, but has not been actually set up. I can do this if you want but not for this low price. Labour is $120 an hour, and if you want me to set it all up on a display board... sure I can. I just mention this as some people think things just fly onto the car by magic. 

Personally, I would have this inside a perspex box so it can be seen ... these electro-mechanical solutions were from my era, and they are just so ingenious... rather than just throwing a flipflop and diode at it. (or glass... perspex is a shitty product... with only the safety aspect making it superior... glass with silicon (a la an aquarium) is far superior.)

****

OK, this is a very USA setup.  Various cars used sequencing  turn-lights... like mid 60s Thunderbirds, and in this case the '68 Mercury Cougar.  

The sequencer electro-mechanical  "brain"... and the huge lights....and some instructions on using the controller/sequencer/etc as well as a circuit diagram.... are all included in this listing.  

The lights are a monstrous 2 foot long by 6 inches high.

https://www.youtube.com/watch?v=sGjpwGl-0qQ

sorry, international, your huge postage of $400... is because... the ONLY way I will send these is with DHL or UPS express (1 week) ... no post office.  These weigh over 10kg, thus the high rate.  If it is less, then I will refund.  Be aware ebay charges 16% fees on postage as well, so $65 of the postage you paid went straight into their pocket. If it is more, then I will advise.  It is simply impossible to know all the variations across the world, so no cry-babies if it is more. eg like europe or middle east... i just don't know all the variations till i look.... you could pre-ask of course.

.