Can weather faxes be obtained reliably from a laptop computer/short
wave radio connection

Yes, it's very easy. We have an old Icom M700 SSB, linked to an old
Toshiba running Bonito's Board Terminal. BT is not cheap but it decodes
weatherfax, RTTY and Morse, with a SYNOP function. No modem needed, just
plug SSB to sound card.

Mike