Hi.. The wires are probably the originals and the tension screws are going to be the 2" variety.. Re the heads I am not sure .. May have just been those with the rectangular Slingerland Sticker or a Remo badged which also had the Slingerland sticker.. Have seen both but I do not know when the change of heads took place.. Someone on here will know .. (Blair may have the tension screws as well).
Big job but you'll have all of the satisfaction at the end..
Cheers