CSNTM posts an image of the binding of GA 2756 (in the possession of the Bibelmuseum in Münster). It shows a stripe of parchment which has been used to reinforce the binding. CSNTM claims this is a "Hebrews lectionary fragment..., single column, approximately 23 lines per column". The text passage it contains is said to cover Hebrews 12:25-28.
We think, this fragment merits closer attention before we can actually say what it really is. At the moment we can confirm it contains Hebrews 12:26-27 and, probably, also parts of Hebrews 12:25 at the top. But we are not positive about 12:28, which should be found on the last 5 lines.
Moreover, we don't think that the comparatively small coulmn containing between 13-18 letters per line qualifies for a one column-layout. It seems more likely that the layout was two columns to the page. In addition, we count only 22 lines and see no way to assertain "approximately 23 lines per column."
Unless, someone comes up with a compelling reconstruction of the last five lines that relate it to a lectionary specific feature, another alternative may be valid as well, i.e., it represents a patristic text quoting Hebrews 12:(25)26-27.