|Finally skimming through my Graphic Converter third party US$10 mannual by Hagen Henke which I bought in April 2002.
I came across the Concat function in File > Convert & modify > Function: Concat.
It can derive a horizontal or vertical or row/column combination montage with a set of images.
I tried it out with a gallery I had handy, the last mac meetup in April. I reduced the resultant image drastically to prevent sluggish uploads but you get the idea.
The first image sets the size so there are some distortions when you combine potrait and landscape shots.
Graphic Converter belies its small size, and I am uncovering gems slowly, and with relish.