Wang paper tape format?

I have some paper tapes that I'm trying to read and I have good reason to believe they are from a Wang machine of some type. They seem to hold some sort of document. The writing on the tape indicates a section number and "pages". The tape is 8-level. The 8th bit seems to be used as some sort of end-of-line or end-of-record marker. The 7th bit seems to be parity. So the actual symbol codes are likely 6-bit. I've read in the tapes and done some cryptanalysis but so far I haven't been able to see any patterns that would suggest groupings of letters at certain codes. At this point I'm confused. Does anyone know how Wang paper tapes were encoded, or does anyone know where there is technical documentation about this? So for my searches online have turned up empty.