I'd say the best thing you can do is to keep a hawk's eye out for the next month and change. HH tins are all out of stock on P&C currently, but if you have no qualms about rolling the dice with them, they could restock a final cache at a moment's notice.
Alternately, with the final Sutliff wave apparently in transit (or close to it), you could keep an eye out for Sutliff's 759 match, which is the bulk identical twin brother of Black House. Although I would imagine the time window for snagging anything in this final wave would be pretty tight, it still seems the more likely of the two strategies to yield fruit, IMHO. I myself will be looking for the OM match and Plumcake, two blends I will greatly miss.
Best of luck!