Thank you both for the replies -
Unfortunately it seems that this was part of a scam, one a little more elaborate
than usual.
Well at least it's good to learn, even this way, that addresses can indeed be reused!...
In this case it'd be helpful if you people could point out where scam sites involving
crypto can be reported. With a quick search I didn't find anything community-based
but I expect there is some reference list out there. I've already reported the address
and what seems to be its "container" address at
http://bitcoinwhoswho.com Cheers