I dropped in.
I followed expert advice: knock; bring something.
And so I knocked on Mr. and Mrs. Landlord's front door to bring the rent cheque (not the rent check) and a little plate of homemade cookies. With a twinkle in the eye, they invited me in, steeped some tea and we chatted quite comfortably for an hour and a half.
It was lovely! Do they have stories to tell, my goodness. They lived in Holland during and just after the War, he on a farm where they had refugee children from the cities, and she in the north of Holland where Canadian soldiers were stationed. I learned about salting pork, putting pine needles around a rhododendron plant (not too many or the plant will burn) and that without refrigeration, meat (or soup for that matter) should be warmed up every day else it goes off.
Turns out dropping in is not scary after all. I think I'll do it again.
Thanks for the encouragement!