Chimneys for outdoor model railway buildings

A friend of mine has an outdoor garden railroad layout and asked me to print him some chimneys for his buildings, so I designed some and here we are. they were built for 16mm, 1:19 ish scale. Scale to 30% for O gage, 17% for oo/ho (guide only). designed with 3d maker that comes free with win10. but I also used sketchup and now tend to use Tinkercad because its easy and brilliant!