I know what you mean. Only today I found a picture of a Foden with a front so similar that I began to doubt the identity of the puzzle photo. But I've examined it with a magnifying glass, and there is definitely an AEC badge on it.
Yes, it's a Regal III, so the point is yours.
But as I'm feeling generous, I'll also award Otto a point for finding the coachbuilder, but being beaten to it by 34 seconds!
Unaltered photo below. Ivanhoe Coaches were part of Cunningham's Bus Service of Paisley, Scotland. You'll be fascinated to know that the driver is Jimmy Craig, who went on to be manager of the company.