Some Error Sultanate Of Palembang Tin Pitis

Interesting coins @cs. I don't know a ton about these Pitis, but they seem to be somewhat roughly made. Is it harder to find perfectly formed ones maybe?

I must admit: not really my field of numismatic expertise. Malaysia has a long and interesting history of using tin as a currency metal, covering hundreds of years.

Refer to Google Images: "palembang coins", to see some good pictures of genuine coins.

My first thought was: counterfeit.
I have a few genuine tin pitis coins of this general fabric in my collection, to compare with the pictures seen here.
It is easy for a backyard workshop to produce counterfeits, because tin is very easily handled at low casting temperatures.
It seems to me that the coins pictured may have come from a wooden mold. The obvious casting seam around the edge is what I would expect to find with a poor quality counterfeit.

The online version of Frank Robinson's catalog: http://www.fsrcoin.com/palembang.html