In Sivan, I ordered a specially-made table for my digital piano. The company has informed me it will be ready for delivery during the Three Weeks (but before Rosh Chodesh Av). Since I can’t play the piano during this period, and so I won’t be deriving joy from the table until after Tisha B’Av, can I have the company deliver and assemble the table as planned or do I have to wait?
Without getting into the question if you should be making Shahechiyanu or Hatov v’hameitiv, according to most poskim you can have it delivered since you will not be making shehechiynu on it until after you use it, which will be only after Tisha B’av. If the correct bracha would be Hatov v’hametiv then it is permitted without a problem during the three weeks until Rosh Chodesh Av.
It should be noted that according to some opinions there is a preference, if possible, to wait to have it delivered.
Halichos Shlomo (Bein Hamitzarim) 14-1, ftnt. 1, Ashrei Hoish 68-12, M’bais Levi (Bein Hamitzarim) pg. 8-4, Poskim.