We have just made a small batch of Neo Pocket Flash Masta cartridges. We will try to be keeping these in stock through the rest of the year, but (of course) that will depend on demand.
At the moment, we have 13 cartridges that we have assembled by hand. We have most of the parts to make another small batch or two, and we are also working on getting another larger batch manufactured/assembled for us.
I hope we can keep these in stock for a while.
The cartridge shells may be a different story. As you may know, we cut these from sacrificial game cartridges. They are getting more difficult/expensive to obtain. At least we have the 3D Printable Neo Pocket Flash Masta shell available out there, now.