All good advice. If you need parts...Grizzly is a good resource. Not a guarantee that they will be an exact fit but with a little research I was able to get some seals and stuff for my Top-Tech copy of a RF-45 by looking at Grizzly models.... checking out their parts diagrams and then roll the dice. .
It’s rolling the dice. Because of that, I’m not sure of the question as to that theory that everything is made at the same factory. I’m more of the opinion that there are multiple manufacturers who just copy various models. Some of these companies take something like a Rung Fu mill drill and reverse engineer them. Some are better than others. I think there are multiple manufacturers.
But, I’ve heard so many stories that I now say who knows. China is the Wild West in my opinion with rampant intellectual theft and corruption in my opinion.