Be very careful taking that apart. Drop the pan and remove the exterior parking cable housing. Those cables are very fragile these days and nearly impossible to find to replace them.
Yes and No. the roster tails are completely different. Valve body is different on pushbuttons and pushbuttons have a rear pump/drum as where 66-later 727s have just the front. Also, the input shaft spline count is different. It's a finer threaded shaft. Pushbutton trans use a 24 spline input. 67 and later use a 19 if I recall right. There's also a couple extra bushings and gaskets inside the pushbutton. Also, the push button uses a two hole filter versus a single hole in later 727s. Case on cable shifted are different as well. .