Hi guys, this is to show you how I modded my Solitaire using a drop-in led for the AAA MiniMaglite.
One has to remove the original optical assembly and find a lens. I have found two lenses, one convex 10,5mm and this other a double convex lens 10,7. Just add a spacer that doubles as a circlip to hold the lens in place. Made from a zip tie 
Use a 3,3 Volt LiFe battery.
It works like a charm.
More than 40 minutes of runtime
This Solitaire color: Ambar Maglite code LD
Pink Solitaire mod: inverted switch. screw in to switch on.