While much work is proceeding with regard to the preservation and restoration of audio documents in general and compositions for tape in particular, relatively little research has been published with regard to the issues of preserving compositions for live electronics. Such works often involve a distinct performance element difficult to capture in a single recording, and it is typically only in performance that such works can be experienced as the composer intended. However, performances can become difficult or even impossible to present over time due to data and/or equipment issues. Sustainability here therefore refers to the effective recording of all the information necessary to set up the live electronics for a performance. Equally, it refers to the availability of appropriate devices, as rapid technological change soon makes systems obsolete and manufacturers discontinue production. The authors have had a range of experience re-working performances over a number of years, including compositions by Luigi Nono and Jonathan Harvey, amongst others. In this paper we look at the problem as a whole, focusing on Jonathan Harvey's works with electronic elements, which span some twenty-six years, as exemplars of the types of problems involved.