XPAN 30mm viewfinder is famous of its drying out problem. The spare part never be seen in the market, it makes the repair impossible. The spare viewfinder is hard to find and at high cost. Besides, all viewfinder will suffer from the dryout problem, because the sealing of the bubble level is not good enough. So it is just a time issue to face the problem. If you are lucky enough, dry out will take long time. If you are bad lucky like me, your like new finder will dry out in a few years.
A cheap alternative solution is external bubble level. It is OK but you cannot check the level while framing.
In order to 100% fix the problem and restore the outlook to be 100% as original, we are trying to remake the spare part. During the studying and making processes, we admire how precise and difficult that the part is made. The manufacturing cost turns out to be 10 times more than expected, due to the high failure rate. The tiny glasses are so thin and small, so it breaks easily.
We decide to make a few pieces. perhaps 10 pieces at the moment because of the high cost. It is a product only for enthusiast.