Basically, the contacts I have are mostly from manufacturers that make lithium ion cells, and the fully assembled cans of 18650, 26650, and 32650 are ready made to be assembled.
So, to get a custom design, you need a massive MOQ to justify making them.
There is one manufacturer that was willing to do this for smaller quantities, but the company’s been completely erased from Alibaba, and I haven’t received any emails from them.
Guess they closed down 