This may be a stupid question,what part of the turkey is the cape?The back feathers?The last turkey I cleaned I skinned and that looks fun to try.

Have you tried Borax? We used to put it on snake skins and pin them and place them in the attic to cure. Don't know if it would be better than salt or not. I am wanting to try caping one this year myself. I've seen some impressive capes with wings attached but that is probably outta my league.

I use borax, does a good job.

I basically skin the bird from the back of the wings including the tail up to the back of the neck if that makes sense. It is all of the back feathers. Just skin as much as you can and you determine what you want. The first pic I showed was my biggest bird which was 26.5lbs and I skinned him from the back of the wings from neck to tail. Hope this helps!
Treebeard

Please don't take this they wrong way but I had to say something. It seems that from your pics you are leaving a lot of meat and fat on the skin. The use of salt will help preserve this but only the borax treatment will somewhat bug proof it. You should attempt to get all the meat and fat off and then borax it. I don't know about you but I like salted meat and would never eat meat with borax on it.

No offense taken I find it easier once the salt has taken the moisture from the last bits of meat and it pulls nicely from the skin. Borax is the next step in the curing but it is a good point and someone may not understand that so thanks for raising it.
Take care
Treebeard