I share your admiration for those great Doll overtypes. My 510/2 was the first Doll overtype I acquired. I love it and the Doll overtypes are some of my favorite engines. Thanks for the video.
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Very nice!!!!
Do you do anything special to stop so much heat going into the boiler from the vapouriser burners?
Also, do you coat the outside of the firebox with something like Ballistol when you store them to stop rust?