What form of gypsy voodoo magic do you need to use to get a hold of someone at gossen? My 14 year old lunapro digital pouch is turning gummy. I found this out when it was getting crap on my lens. Since their sixtomat meter is essentially the same body / mold, I requested info on getting a new case (hopefully free). Unusually fast self destruction on this pouch.
Plastic is not permanent, but cheap. Certain types go brittle, others outgas, some just fall apart. Plastic can be made well, but then it costs more money. I just unearthed a pair of NEVER WORN Florsheim shoes ( cheap ones) and the soles were sticky. I tried them on a walk thinking I would wear through the sticky. Small stones and leaves stuck and within 15 minutes the soles had TOTALLY come off the shoes. Landfill.
However, that Gossen already stopped service of your meter itself indicates that they assume it to be over its time already.
That attitude of them might apply on the pouch too...
(One german car manufacturer still offers spares for 40 years old cars, Durst in one case stopped servicing a product the same year it ended production of it...)