As far as I'm aware spares for the 100 are almost non existent. I have rebuilt/re-engineering a couple in the last few years. The compression cylinder to the valve block sometimes develops a slow leak. A Feinwerkbau 600 series valve seal will replace the standard part other than that your into making your own replacement parts IIRC although I seem to remember the transfer port seal can also be replaced with a standard service part from another make?