Another XML gallery Q

Hi!
I have used the gallery tutorial and modified it to include additional text fields and resized/positioned everything with no problems.

The problem I am encountering now is the inability to load thumbs of differing widths. I have tried to source the width of each thumb to no avail.

My thought was, instead of using the dimension of the first thumb to base the distribution of the following thumbs, grab the _width+5 of each preceeding thumb so you can have a variety of thumb widths.

Is this possible or am I SOL?

Danke!