Hi Dale, long time no see :-)
My wife and I still use the ROF in cold weather, inside our tent. Sits securely on the floor, won’t spill. I stopped making these when my in-laws had health issues. Slowed me down some. Never made more, container started show signs of rust after a year. Mine works fine with rust, gives it character :-) Looks “vintage”
I suppose using carbon felt would suffice if someone wanted to venture making the stove. 17ml of fuel will heat 2 cups under ideal conditions using a Fosters pot. Sure wish they would reinstate the original Heineken barrel design.