I've made them with empty Lynx cans in the same way, they're getting smaller every time I make one but I'm currently at ...
46mm for the outer (base of the Lynx can)
43mm for the inner (top of the Lynx can, cut under the thick silver nozzle ring)
A bit of JB Weld and then 0.5mm holes drilled 5mm apart all the way round, 5mm below the lip.
I'm about to build a couple more so I'll take some piccies this time