DIY Plastic Injection Molding at Home. I'm using my AB-150 injection molding machine, made by A.B. Plastic Injectors in Canada: https://www.abplasticinjectors.com/ab-150
I have a number of molds 10 years ago for a model train kit called the Dolores Conoco Plant made in HO and S scales by Ragg's...To Riches: http://raggstoriches.biz/CONOCOPLANTsidepage.html.
There lots of tricks to home/DIY injection molding, and it's not hard. Nor does it take a huge investment to get started. I made these molds with a Taig CNC machine (that I sold a few years ago).