Hi Titanic
I am not an expert on hog houses, and I have never seen that particular hog house, but imagine it is worth a try. Wasn’t sure from the diagram whether the back was enclosed. As you say, if it was from the PTES it should be ok, although not sure about it being plastic – non breathable? I just wonder whether hog house design has moved on since then? The main thing is, though, it will provide shelter. It seems a shame to waste it, even if it is only used as a shelter for hogs visiting for feeding. I keep a couple of hog boxes near where I feed the hogs, and they often nip in for a quick nap before, after or between feeding, especially at the beginning and end of the hog season. They seemed to find them particularly useful when we had some heavy rain one night recently. I saw some very bedraggled hogs nipping into them! I think some people also use hog houses for putting the food in and it should be fine for that.
Good luck with YOUR new house and garden and happy hog watching.