Aren't esbit similar to the fuel tabs that come in the MRE? I can't recall the name of the chemical in those, but don't want to open a ration to find out.
I also have an older boy scout camp stove, complete with esbit branded fuel tabs.
It seems like many of todays “fuel tablets” are some derivative of the !936 German Hexamine invention (according to Wikipedia). I would have imagined some improvement in the subsequent years, but maybe the basic original formula is good enough for most applications ?
I ordered a box of Esbits on fleabay titled Trocken Brennstoff Solid Fuel. There is also a Coghlans fuel tabs that look like big aspirins.
I figure if civilization here in the USA keeps approaching Mad Max & Fury Road levels of anarchy , I can take the Jensen 75 with Esbits deep into the forest . I can belt up a dc generator to charge the cellphone, boil some creek water, and use the steam to make expresso. I wonder if the top of the boiler gets hot enough to cook squirrel meat ?