I got a early #20 from my brother and it was a basket case. Missing the lamp base, smoke stack, bayonet whistle, and the bayonet pressure valve's arm was busted off & gone. Talk about a challenge but I got it to run!
I got reproductions / replacements for the whistle & pressure valve, which both have their issues. Poor fit, leaking, and not true reproductions. I borrowed a lamp base and stack from another engine. Then I ran into problems where the arm of the piston was out of place, that took me a bit to figure out. Then the piston rod would jam, so I can to take the end cap off (which I HATE doing) to clean crap out of the piston area.
During the video, I am pretty sure I was running low on fuel, since before I started the video it was running slight better. Regardless, its running and likely had no right to ever be ran again ;-)
Hope you enjoy!