For a deeper dive into the history of ARPANET cartography, check out this paper (many more maps inside!):
Fidler, B., and M. Currie. “The Production and Interpretation of ARPANET Maps.” IEEE Annals of the History of Computing 37, no. 1 (January 2015): 44–55. doi:10.1109/MAHC.2015.16. http://ieeexplore.ieee.org/document/7057559/?arnumber=705755...
I believe that I own this watch and it didn't ask me to sideload an APK. Rather, the watch displayed a QR code that pointed me to an app the Google Play store. There may be something shady going on but the evidence here is not clear cut.
Unfortunately, no. There is no comprehensive archive. There are bits and pieces on the web plus several Fido boards still running with archives going back a decade or so.