ok, i seem to be a little deeper down the rabbit hole. I managed to use putty to input the wifi creds (I have two cores and can see both mac addrs listed in my router's status page so I know the "bad" core has connected to it). I also extracted the id and put that back into the cloud (through the build IDE). Now when I power up the core up it flashes green (connects to the router) then if flashes blue real fast, then a series of red flashes (I can't quite count them because some are fast and some are slow - if I had to guess is does an SOS then a single red flash [then repeats the SOS + single red flash]) and then there is a single white (grand finale) flash at which point it repeats this whole sequence starting with green.
I'm guessing I need redo the keys now but (a) I'm not 100% sure if I should be going in that direction (I'm not getting any orange lights) and (b) if I should go that way then dfu link is broken in the posts i've read:
Thanks!