Well, these are triode EL34s, so you sure don't need 10W output transformers!
You could see if Magnequest can make you a pair of Robin Hood transformers for this project. The last pair that I bought showed up in about a month. Really though, the 10W Edcor transformers that you have don't have the best bandwidth specs, but you also have to keep in mind that these numbers will improve as power drops, so they are likely just fine for what you're up to. (Which is operating under 2W)
On the power transformer, I'm guessing the 12AT7 is heated with the 12V winding and the EL84 heaters are stacked in series to also work off the 12V feed? If so, why not just leave it as is?