Interestingly, found this email archive while nosing around: https://m100.bitchin100.narkive.com/yM6Z1vcJ/spreadsheet-program-for-model-100
Rick Hansons's advice: "Download the files as if they were .txt files to your PC, then move them over to your Model "T" as .do files, load them into BASIC and save them as .ba files "