Don't worry I just did similar on another thread !
And yes, KLM were an early DC8-53 operator. After getting an initial seven series 33 in 1960 they received five DC8-53 in 1961, with more in subsequent years.
These five DC8-53 were not a particularly lucky batch of aircraft; one was lost near Lisbon when only 30 days old, it got into a spiral dive in night IMC and crashed into the Atlantic, so the whole batch was never in service together, while another blew up in a hangar at Amsterdam a few years later while repair work was being done inside a fuel tank.
If you want all the rivet-counting detail
it's here :
http://www.planelist.net/dc-8.zip