Re: Why now?
He must be very rich, there was also a perfectly restored 88mm gun, yes the one setting 1000's of allied and russian tanks of fire. These guns are very rare and expensive collector items.
It is unknown on what information it was decided to remove the material from the house and take it to an army compound for further investigation. Since the value of a 88mm would drop considerably in value from a demilitarization, perhaps it was not implemented to the full extend required by the law, not taking into account that destroying a perfect 88mm is a barbaric act.
May be some civil servant saw reason for that to rob an old man of his possessions.