I recently swapped out the spring back to my 1947 Pacemaker Speed Graphic for a Graflok back. Neither back had any felt placed between the back and the camera, although it looks like there are channels for felt about 3/16 inch wide all around the rim of both backs. Could anybody verify that, yes, these Graflex backs had felt between their backs and the camera bodies? It seems to make sense that they should, but maybe Graflex decided to save a buck and send their Pacemakers out into the world without any kind of a seal between the back and the camera body?

The back frame is a direct fit to the wood body, no felt or other material between. There will be no light leak unless the body or frame is damaged.
The 1/2 inch long screw (3) goes on the bottom of the frame, the 3/8 inch long screws (2) go on the top; both #2. The graflok takes an additional screw that the Graphic back did not use, its a #1- 3/8 inch long flat head that goes in the film insert opening.
The pilot drill for a #1 wood screw is 5/64.
#48 drill .076
5/64 drill .0781
#47 drill .0785

45PSS wrote:

. The graflok takes an additional screw that the Graphic back did not use, its a #1- 3/8 inch long flat head that goes in the film insert opening. The pilot drill for a #1 wood screw is 5/64. #48 drill .076 5/64 drill .0781 #47 drill .0785

Both of my backs use the extra screw:

https://speedgraphic.shutterfly.com/pictures/31

https://speedgraphic.shutterfly.com/pictures/31#32

The back of the Graflok has two strips of felt where the attachments mate to it. I just assumed that the very nicely carved channels on both backs would have used the same felt. That's why I asked.

Side rangefinder versions: http://www.graflex.org/manuals/
Top rangefinder version: http://www.southbristolviews.com/ >photo related > Graflex Manuals and more

I do not recall any felt on the graflok back, someone may have added it. Felt is not listed in the parts list. Velvet in the film holder seat is standard.

45PSS wrote:

Side rangefinder versions: http://www.graflex.org/manuals/ Top rangefinder version: http://www.southbristolviews.com/ >photo related > Graflex Manuals and more I do not recall any felt on the graflok back, someone may have added it. Felt is not listed in the parts list. Velvet in the film holder seat is standard.

Thanks! I really appreciate your expertise and knowledge. You make it possible for guys like me to even attempt resurrecting these old cameras.