Q12 is a 2SC1815 - an asian type. Looking at the flat face, left to right the legs are Emitter - Collector - Base. That NTE thing is I do believe a US type transistor with the legs Emitter - Base - Collector. So unless you put it in sideways, the legs won't be right. And since Q12 controls the mute for the output stage, I don't doubt the amp is quite.
Why replace all those transistors, was the whole row of them fried? or were you on an easter egg hunt hoping one was bad?
May I suggest getting away from that NTE stuff? The 2SC1815 is one of my favorite transistors. It is a great general use NPN part and it is low in noise as well. Rated 60v, it will work most anywhere an NPN signal transistor is needed with an Asian footprint. Next time you order anything from Mouser, tack 10 of those onto the order and have them. Mouser stocks them for 22 cents, if you buy 10 of them they drop to 17 cents. Start building a parts collection. The PNP complement would be the 2SA1015. Those two alone would cover most signal transistors in the Asian types. get a few American types too, and in one little row of drawers you have everything covered.