While its not a moral thing to do, in the end who care so long as you werent caught by the one who had the set, it aint hurting no one if they dont notice any difference. If he doesnt appreciate the sets fully, there are those who will.
I would laugh if the dude used these boards and found out about his lost parts this way. The reactions would be at the level of Indian soap operas.
As a kind note, never say you stole something to people on the net. Thats never a good thing to do despite being the "honest thing" to say (messy moral nonesense and all that). We dont need to know how you got it, we can just live by that you got it in general.