A sticky question...
What is that old thing, CAR3? You have some really grey areas in that, stuff that just wouldn't be allowed today, so that I doubt it would be economically doable to recerify this machine to the latest standards. There is nothing wrong with that; have a look at what Boeing do with the 737, for instance.
When you get involved with the DC-3, is that ever another world. That thing doesn't even have stall breaker strips and I had Mr Training Captain Ironbutt McHardass telling me that "You young guys (I guess I was only 32 then) don't know how to do a full-breaking stall but show me whatever you can..."
Just a short time later there we were looking at all green in the left front windscreen and all blue in the right front windscreen as we were ploughing out of the sky over the Florida Glades with lots of down and not much forwards, full right aileron but not a lot of change happening in my lousy little life. "So this is why they put stall breaker strips on modern airplanes!" was most of what was going through my tiny mind. No telling what was going through his but the rest of the ride was much quieter! Then you have its ergonomics, from before that word was even thought of, and it shows!
Sit there staring at your new glass panel and be happy, is all I can tell you!