Worst case is that I will have to resort to using this old machine to access the boards and will have to resign myself to never sending any more stories to the boards (since I do my writing on the pc).
No!
Tank, you can access your email account with your 'normal' pc, can't you? Copy and paste your stories into a new email and use the "Save as draft" option - or send it to your wife. That way, you can access your story from your olc iMac. That way, you can copy and paste it again onto the board.
(I've been using this technique for a while for university stuff - the computers there only have disk drives, and my laptop doesn't have one of those old-fashioned thingies any more.)