For the accessory turn signal unit you need to look for the Guide 6004 (color and applications differ).
https://www.flickr.com/photos/advance-design_parts_co/8129435258/in/album-72157631868452754/
https://www.flickr.com/photos/advance-design_parts_co/8129416019/in/album-72157631868452754/
https://www.flickr.com/photos/advance-design_parts_co/8129328270/in/album-72157631868452754/
A RH light option was available, only a couple of states Oregon and Washington I believe required them in this period of time. This optional item in NOS for 1947-53 is very rare. The RH light was not furnished in the accessory signal kits I have owned. Companies other than guide offered these lights here is one example.
https://www.flickr.com/photos/advance-design_parts_co/16201073413/in/album-72157631868452754/
The later '54 style kit came with everything needed for the conversion (rear).
https://www.flickr.com/photos/advance-design_parts_co/22702548351/in/album-72157631868452754/
The separate '54 light was also offered separately from the signal kit and is more common NOS but not cheap.
https://www.flickr.com/photos/advance-design_parts_co/15240467973/in/album-72157631868452754/
There were many different styles of aftermarket signal kits available, here is one example. These are very common NOS on eBay and at Swap Meets.
https://www.flickr.com/photos/advance-design_parts_co/16453032716/in/album-72157631868452754/
Period advertising showing front fender signals on a GMC. Lights in mounted locations are rare in the factory literature.
https://www.flickr.com/photos/advance-design_parts_co/15305984747/in/album-72157631872034068/
A shot from the 1954 Silver Book, several examples can be found in the Silver Books.
https://www.flickr.com/photos/advance-design_parts_co/16273739804/in/album-72157631872034068/
1953 mailer/dealer handout.
https://www.flickr.com/photos/advance-design_parts_co/23903473622/in/album-72157631872034068/

1950 Chevrolet 3/4-Ton 3600
More pictures on Flickr