Sheldon, thanks for your good wishes!

1) It seems that the platforms were not new, but were in fact built in right from the beginning. Rashi writes here that the platforms are considered the same as the floor. Rashi Zevachim 35a (just before the Mishnah) writes that the platforms were high and built of stone, and were part of the floor.

2) The sefer Netivot Hakodesh (available in Otzar Hachochma) on Zevachim 35a (paragraph beginning v'La'avodah) cites the Gemara Zevachim 24a which tells us that King David sanctified the entire floor of the Beis Hamikdash. Netivot Hakodesh writes that David also sanctified the platforms as part of the floor. As soon as the courtyard of the Beit Hamikdash was built, the platforms were built together with it and became holy.

Best wishes

Dovid Bloom

Follow-up reply:

I found, bs'd, that Rav Yosef Shalom Elyashiv writes in his Notes here, that one has to say that these platforms were a Halacha l'Moshe MiSinai; they were a special law transmitted by Hash-m to Moshe on Mount Sinai; because otherwise there is a principle derived from the verse in Divrei Hayamim 1:28:19 "All this I give you in writing, as G-d has made me wise by His Hand upon me"; that one may not add on to the courtyard of the Beis Hamikdash (see Zevachim 33a).

We see again from this that the platforms were a part of the very original plan of the Beis Hamikdash.

KOL TUV

Dovid Bloom