I don't believe Protek is an OEM, my understanding is that they are a distributor in similar fashion to what OFNA used to be where they rebrand custom orders from generic manufacturers in China. I can probably point out close to a dozen different OEM's of their rebranded products. Protek is vastly overpriced (middle-man) where you can get the same product (different label/packaging) direct from China for a fraction of the price.

If you go onto Alibaba, you can make your own custom rebrand if you make a minimum purchase of X number of units, that's basically what Holmes Hobby did. I don't personally know Holmes Hobby, just explaining how the process works to my understanding.

*** UPDATE
Here is an example of an AGF servo where you can get a custom Logo/packaging if you order 200+ units:
https://www.alibaba.com/product-deta...6e253a87y1NOwf