Yeah, as I read the minicom comment above, I was thinking “kermit”. I always use kermit in preference to minicom to speak serial to devices, because it just feels more like I am in control of what’s happening. It probably just boils down to my preference for command-line interfaces. I like “set baud 9600” better than “Control-A, o [look at menu] [down][down] [look at new menu] e”.
However, it seems to me that using UUCP for this mission would probably simplify the scripting requirements. No need to script the dialing and transfer of files, because UUCP takes care of all that. Just build a script on the remote end and then “uux remotehost!loaddata