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

@charles-m-hill Iam interestred in the fender skirts and spinner steering wheel. Let me know what you want for them. Thanks,Al

Charlie is this really you!   Welcome back if you are the one that has the sarcastic posts about anyone's car that isn't a 41.  We have missed you!

@john-schildberg Yep, it's the Fulton lover himself. Seem to have mellowed somewhat though.

@dennis-christianson I would like to add turn signal to my 1939 Chev, coupe.  Looking at one from Chevs of the 40s.  Item#9857207K.  37-52 Turn Signal Kit, 6 volt Without Harness.  Also 7 wire unit.  Would you have any additional advice other than what you included in your on-line message?  Might you suggest an on-line  instruction or video reference?  My VCCA member # 35178   Gary Lovell   Thanks