A side valve (flat head) engine is an engine is where the camshaft and crankshaft is both at the bottom of the engine block, the valves are also fitted in the engine block and the cylinder head is flat with the sparkplugs standing upright in the cylinder head. Search the internet for either side...
Someone posted a link recently for the old john-tom site. the plan is on there. https://web.archive.org/web/20220123220452/http://www.john-tom.com/html/ElmersEngines.html
I have the 35 Steam pump plans previously downloaded from John Tom website, if there is no legal reason why it cannot be posted here, I will post it. It was a free download from John Tom. The moderators must please comment.
Someone might have tried to make a compressor of the engine. There seem to be a v-belt pulley groove on the attachment next to the flywheel, a pipe coming from the injector position and a nonreturn valve( might also just be a T) in the pipe.
There is plans for a roller similar to Rudy's Copperhead steamroller by Julius de Waal, see link.
https://modelengineeringwebsite.com/Coffee_pot_roller_2.html
Stoogroep Holland also have plans for a smaller steam truck Endeavor. The gentleman at Steam and steam models (french) directed me to https://www.cav-escarbille.com but i have had no response fro them. Does anybody know if the website is still active?