I've added a clarification to the end of the post on whether angzarr might be found in the Cambridge Library document, which I mentioned in my twitter thread but not in the post:
> Furthermore, the Rare Books department tells me that “unfortunately none of [the materials] seem to mention S16137 through S16237”. It’s possible the glyph is listed without its serial number, but it’s equally possible that this document skips that range altogether, just as 4-Line Mathematics had.
I'd also like to point out that Cambridge alumni are unlikely going to be able to request scans for free; I think you need to be a current faculty or student.
> Furthermore, the Rare Books department tells me that “unfortunately none of [the materials] seem to mention S16137 through S16237”. It’s possible the glyph is listed without its serial number, but it’s equally possible that this document skips that range altogether, just as 4-Line Mathematics had.
I'd also like to point out that Cambridge alumni are unlikely going to be able to request scans for free; I think you need to be a current faculty or student.