Thank you Dave R. That did help... although I won't know if I've got it right until I pick up the print from the commercial printer later today! My other problem was that the template I had made was not configured properly. Thanks again.
@dave r said:
The SketchUp viewport initially shows in LO with the proportions of the drawing window in SU. You can drag the edges of the viewport to resize it to suit. Select the viewport and, in the SketchUp inspector window, make sure you tick the box to prevent the scale from changing as you drag out the sides of the viewport. I would drag them out toward the edges of the paper space first and then set the scale to 1:1. You may find you need to do a little additional tweaking of the edges of the viewport after setting the scale. I would work to get the viewport edges as close to the model as possible. Then, under Arrange, you can center the viewport both horizontally and vertically.
Make sure you change the scene selection in the SketchUp Inspector window from Last Saved to the scene you've selected. DO NOT double click in the viewport before changing the size. That will break the link between the scene in the SU file and the LO viewport. Generally you never want to see the word [modified] before the scene name when looking at it in the SketchUp Inspector window in LO.