An interesting comparison was the Kiwi AF Herc program. They had five H models that were around 50 years old and they did some big upgrades including replacement of the wing centre sections and other areas but still got to a point where with such a small fleet they'd be lucky to have one or maybe two serviceable. The USAF has had a big H model refurb program including new props and cockpits but this was to carry a much deleted fleet through so they could acquire more J models. Other users such as Denmark and Norway rolled over to the J. It looks like Holland is just playing catch-up.