"I will have to ask some advise here, I was under the impression that a cape gun always had two barrels of the same bore, with one rifled and one smooth and if one barrel was a different calibre/bore it was then a combination. If I am wrong could someone explain the difference between the cape and the combo please."

Not an expert but my understanding is the term "cape gun" obviously originates from the "Cape" of South Africa and describes a side by side firearm with one smooth bore barrel and one rifled barrel. Not necessarily the same calibre.

A versatile firearm for mixed game hunting especially for sustenance when small game and birds might present themselves or antelope/medium sized game.

In reality the same thing as a "combination gun" except the "combo" is more usually an under and over. "Cape Gun" is probably a more "romantic" term for a side by side combination firearm.