There is actually a guy looking into that now. https://www.seymoronion.com/index.html Really cool guy to deal with too.
I am in disagreement with his current plan, and wish he'd consider skipping his interim step of a modified CD case. Quick explanation, he wants to make a CD tray style insert for a standard CD case, which has an instruction style clasp to hold the HuCard. Then, he wants to move into full reproduction of the original style of cases.
Essentially, you need to have a TON of cases made to make it cost effective. Thus, by promising original style cases, he is reducing the amount of people who will pay for these non-original-style cases, leaving him with a massive unsold quantity, which reduces his capital to spend on the original style (OS), reducing the chance of OS cases ever being made. Then, if or when he gets the capital to make OS cases, the NOS cases will never sell. Why buy a NOS case when OS cases are available?
Don't get me wrong, he is an awesome dude, and I love his hucard sleeves. I just wish he'd consider the fault of starting with a case that is overall less important to the turbografx community.