Keystone in a 1590b with no cuts to the box or tray if that helps
Yes, the Dual 18650 is hunky dory, its the Dual 26650 from Keystone that looks like it will need hack to bits for a 1590b
But, ordered a 3D printer today, so I should be sorted with some custom ABS printed battery sled, think Dual 26650 1590b will be my first project, all day unregulated chain vape!
I may be hitting you up