Jerry Howell does the "Farmboy" engine plans which are for a barstock engine that will actually look like it was from castings.
Model Engine Builder Mag will sell digital back issues two of which contain drawings for the "Zero-six" which can be made to look more like it was from castings if it is a bit too much like a barstock engine such as mine. They also have plans/articles for teh Gem & Finney engines
Although not strictly a hit and miss engine the "webster" is a popular first open crank IC design that can be found on the web. The Kerzel is also quite popular and a small H&M engine that plans can be found for.
Might be a bit much for a first hit and miss but the J&E Junior plans are free to download
Depending on how much effort you want to put in then a lot of the engines from castings can also be done by fabrication if you are that way inclined.
Edited By JasonB on 16/07/2021 17:08:57