at what point does all this cutting and replacing lead to problems with affecting the end value of the car after restoration?? Your work actually looks awesome to me. The biggest one I would worry about is the new shock towers and getting them back to original position.

if your going to put 10's of thousands into a frame off resto I would want a better donor car.

lastly and this is just an opinion question. I have always been a chevy guy, loved the chevelles. but recently the 67 and 68 model mustangs have really grown on me. as far as original build quailty were these better cars than the chevys? For some reason the mustangs seem simpler and better put together.