So, there is one thing that has been bugging me the last couple of years (more or less). 

Back in 1988, when I was the ripe old age of nine, me and my family went to Rhodes, Greece, for vacation. First leg was from my hometown down south some 300NM to ESSA. After an over night stay at ESSA we did the next leg to Rhodes. I do believe we flew with SAS but frankly I have no idea and my parents don't know either. I have this memory boarding through stairs at the rear end of the aircraft (however that could have been on another occasion entirely).

I do, however, remember the tremendous acceleration when we headed down the runway for the take-off (way more than the first leg). Rear stairs also makes me want to think in terms of the 727 (and if I am not entirely mistaken those hade some great oomph from those engines). But I don't know if SAS had those. It was probably not the only aircraft with rear stairs either. 

Knowing there are some *really* knowledgeable people in these forums I would like to ask what type of aircraft I might have done that second leg in. 

Pretty sure it would be a Sud SE-210 Caravelle III, here's a pic of one at Heathrow 1972. 

 https://commons.wikimedia.org/wiki/File:Sud_SE-210_Caravelle_III,_Scandinavian_Airlines_-_SAS_AN1809005.jpg

 

I believe that SAS stopped using the Caravelle around 1974, other possibilities could have been a Sterling Airways B727 or - most likely - Scanair MD-80?

SAS had lots of DC9s around that time, and possibly already had some MD80s.