I posted this on the Marlin site but you guys are just as smart as they are. Here is the issue. I've old eyes and now use optics and ghost ring sights a lot. To do so on my Marlin Camp 9, I installed a red dot on a Weaver rail atop the receiver. The first red dot worked fine and was right on but I felt it was too fragile and I could no longer see my iron sights beneath it. I don't trust battery devices or optics in the field and want back up sights if possible. Photo 1 I then countersunk the rail screws deeper and changed to a sturdier red dot (AR take off). I am again zeroed but still have the iron sights problem to solve. Photo 2 I want to use the gap under the red dot like a ghost ring ( a laid over D shape) but, I am 3/16 " too high at the rear and looking at about the center top of the front sight hood for the proper front sight elevation. Photo 3 Deadly aim on my wife's toaster. I can only see the top edge of the original properly adjusted rear sight. It would be removed as it won't adjust high enough. Removing the hood and using a much taller front sight insert would work but I'm thinking buying or making a 3/16' spacer to raise everything in the front and keeping the hood for protection. Does anyone make something like that or has anyone done something similar? After more research, I'm going to go with a .500 front insert to gain my 3/16", loose the hood as it would then need to be a monster, and set a blued cut off finishing nail head or a F/O tube in the valley of the Weaver rail as my rear sight (1/8" high bump). I'm open for ideas/thoughts as I usually need adult supervision. PS. The nail head gets lost from view so the F/O light tube will get tried when they arrive. Note: Regular plastic F/O gains no light from exposed sides so it won't work.