...where does that come from?

I have to stick my hand up for that. There actually was a department store called Gorringe's, near Victoria in London. It closed a few years ago,

The name Gorringe isn't that unusual - google it and a fair number turn up, including a Major-General in the Great War. And there was a British military in the Boer War called "Gorringe's Flying Column" (I never knew the British went in for Flying Columns".)

For the plural "oranges" there's an acceptable enough rhyme in "porringers", a kind of dish.

Here's a wikipedia list of words without rhymes. (It suggests that "door hinge" could serve as a rhyme for orange.)