I'm a french guy who practiced chastity a few years ago with my wife. I had a custom Queen's keep device from Mature Metal that I was locked in for weeks (very easy to clean without ever removing it). Best memory was when I was locked for 2 months before our wedding. Unfortunately Paris was hit by terrorist attacks in 2015 and there were metal detectors everywhere for some time, so we pretty much stopped. After that, we had a child and the fun stuff was put on hold. I hope to find a new custom cage (metal detector proof) and start kinky things again. My wife is tired of my masturbation habits and I cannot make myself stop without a cage, so now might be a good time.
Welcome! I hope you and your wife manage to get back into the game of chastity. You might need to 'sell' the broad range of benefits that she would get, as her perspective and motivation may have changed. Maybe ask her to choose the cage and a very nice key she can wear as a pendant? Bonne chance!
Update: my wife agreed that a new cage was a good idea, but set some conditions : - it should not hurt me - she should be able to tease me in it - she should be able to lock/unlock me easily herself (that was a concern with my previous device that was very secure but hard to remove or put on) It seems fine to me, so we will see if I find a good device.