Even if the music rolls, which are over 100 years old, are often still in good condition, many rolls have minor or major defects due to multiple use. In the case of smaller defects, the rolls can be repaired with reasonable effort. Often the hook is torn off. Repair kits are available for this purpose, consisting of a new hook and an adhesive triangle for the beginning of the roll. If the music roll is torn, it can be repaired with a special repair tape from the book restoration department (e.g. filmoplast P from Neschen). Do not under any circumstances stick with commercially available adhesive tape, as these attack the paper, are not flexible enough and shrink over time, irreparably damaging the roll. However, once a music roll has been repaired, it should be handled with care, as further defects will usually occur during playback.
At Stanford University (USA), defective music rolls are carefully repaired for digitization. Here is a report.
If the note roll shows more severe deformation or cracks on the sides, it can no longer be used sensibly, because the track control cannot work properly and the roll will run repeatedly. This also cannot be repaired well. The same applies if larger cracks or deformations are found in the course of the perforations. In such cases it is recommended to scan the roll and have it re-punched. Even severely defective rolls of music can be scanned and preserved with appropriate effort. If a roll flank is missing, it can also be replaced with most types - QRS offers a repair kit for their 88 rolls (QRS Cat #46002).
At that time, particularly robust and durable papers were used for the music rolls. Over the decades, this paper has also aged, occasionally stored too damp and generally dried out considerably. This results in shrinkage and distortion, which prevents an error-free or faithful reproduction of the original. The roll runs off the track several times and the piece sounds wobbly. In such cases, it is recommended to have a copy made, since errors and inaccuracies can be worked out during the scanning process.
Then as now, the correct storage and handling of rolls avoids the need for repairs. Even with the best storage, after 100 years a reel will no longer be perfectly usable. For regular use, therefore, the use of high-quality new die-cuts is recommended.