Yes you will want a 7 wire switch, I have 4 cars I have installed turn signals on. I bought from the Filling Station or Chevys of the 40’s. Get the better one that has the indicator on  the housing, they come with good instructions, but I wired mine through the ignition switch. They will show it to be wired so the 4 way flashers will work with the key off, but you could also forget to turn the turn signals off. Don’t remember the brand. All of mine I changed the socket in the park lights to use the 1154 bulb.

@dennis-christianson

Dennis,

Thanks for the reply. I'll check out both those sources and see what they offer as well check out eBay.  I have a couple of the factory ones but they are for the next generation of about 42-50 or so.  Number 600 and another diget like maybe something between2 and 6 I think. I may try to install one of them if I can find the inructions and/or a scmatic.  If not, I'll sell them because I want need them.

Have you noted the asking price of the original 1940-41 turn signals for sale on eBay.  Over 6 grand.  More than my car's worth.  Well amost. Wonder if the seller would be interested in a set of 41 fender skirts with the short pieces that go between the skirts and the rocker moldings.  Might even throw in the spinner steering wheel. I don't like it anyway.That's too much for the 41 coupe. I have the original signals on the 41 cabirolet.  Oh well.  Thanks again,  Charlie