Practice and patience will teach you the "right way" - but you'll also come up with your own little tricks. I can now re-assemble mine without having to refer to the Internet - but it wasn't always that simple!
If the Mk IV had been available at the time I bought my III, I would have bought the IV and not looked back - but now that I know how to deal with the III, there's no particular reason I'd want a IV over it.
Old Bill got the Nambu styling pretty well!