The hit and miss IC engine castings at many companies show an "Out of Stock" label.
Some of the popular engine kit types such as the Ball Hopper Monitor, are pretty much impossible to find these days.
All is not lost in the hobby though.
Almost any old engine design can be recreated in 3D modeling, patterns printed with a 3D printer, and then castings made in gray iron, in a backyard foundry setting.
I can show you how, for those interested in learning the process.
Make your own casting kits.
Unless you want to do bar stock builds only (Jason does a magnificent job with this method), then making your own casting kits seems to be the only way forward in the hobby for the future. Even JasonB is getting into making his own gray iron castings, or making patterns for the same.
Ministeam have not cast anything for a few years and Doug was looking to sell off the patterns for all the engines in his portfolio so consider them out of production and possibly not likely to be produced again given the high cost he was asking for the patterns etc.
I do know of someone who is cutting a Galloway from solid on his Tormach CNC