Good on you for doing what you can to keep playing smaz.
I couldn't play properly for a quite a few years due to medical reasons and I missed it a lot.
The orthosis on the picture is made of thermoplastic tape. I really know nothing of it (and maybe it's dreadful idea and if it is I am sorry). I have only seen videos of how they are made: The tape is soft when moulded to the finger, cut to the desired shape around the finger with scissors, and hardens when it has cooled and keeps its shape. The unwanted parts looks to be easily cut off with a scissor after this.
The tape used on the picture is called Orficast, made by a company called Orfit. (I have no knowledge of this company and there may be better products of this kind). The thinnest tape I saw is 1,8 mm thick, but on the videos I've seen it looks like it is to be folded. Don't know if this is always necessary. There are videos to be found on YouTube showing how the orthosis are made (search for Orfit Industries)
The way it's been made on the picture below may be of interest to you I thought, if modified slightly to help support the distal joint better from the outside.