Mature Metal discussion

I am aware that numerous members have shared their stories about entering the world of chastity. Here is my personal account, then. A few years back I opened up to my wife about wanting to be locked. She was a bit unsure and hesitant at first, so I handed her the “key holders guide”. Big error on my part!! She interpreted it as leaning heavily into d/s and FLR (Female Led Relationship) dynamics, which just wasn’t quite right for her. After some time that initial interest started to fade. Last year we talked about chastity again, looking at it more practically this time; I also have a higher libido than she does. After talking it over my wife agreed to let me order a custom cage. The sizing rings from MM arrived today, and I’m currently wearing the 1 7/8” base ring. It has been on for eight hours now, and already it feels like nothing there. The 1 3/8” ring contacts my penis all around without squeezing too hard, while the 1 1/4” one feels a little snug. I’ve been tracking my length over the last few weeks. It varies between 3”-2 3/4”. So I figure I’ll choose a cage length of 2 1/2”, with a security screw included. Given those sizes, what do you all think? Do these order dimensions seem correct? Any advice is greatly appreciated.