regarding esbit fuel , I probably have 10 lbs of it now (as I never use it !) , many sellers praise the amount of esbit they have to send along with the engine , I have actually sent them a message on occasion & told them to just keep it.
I use it in my Jensen 76 as it was my first engine found at my great-grandpa’s, so it brings back memories of running it... fun to use now and then, like adding coal or wood.
Also let the kids use it in some old beat up Wilescos and Mamod TE’s/SR’s outdoors.