The images show a strange (at least to me) symbol that appears in a Hellenistic inscription I’m working on. These are tomography images of an inscription on bronze; the right one shows a tracing of the symbol to make it easier to distinguish from scratches and other apparently irrelevant marks. The general context is a technical astronomical text, while the specific position of the symbol suggests that its function is either (a) standing as the abbreviation for an astronomical term, or (b) acting as an extension of the standard Greek alphabet as a way of indexing parts of the text. I would be most grateful for any suggestions or direction to similar symbols in inscriptions, papyri, or Greek manuscripts.
Could it, for example, be a variant of the T-shaped form of sampi, tilted instead of upright?