That sounds correct.
Landscape will use the width of the page size as the vertical dimension and the height as the horizontal.
Since your custom page size is wider than it is high, if you want it to appear that way, you need the portrait orientation.
Your 176 by 80 mm custom size assumes that you will be feeding one of the long edges of the check first into the printer.
I have found the fault.
The document opens in landscape orientation but portrait is highlighted in page setup.
To achieve what I want, I have to select landscape, this turns the page 90 degrees and in portrate orientation, I then close it. I then open it again, (its still in portrait) and select landscape and we are as I want and ready to print.
My printer is selected off until I am happy I am going to get what it says on the tin, so its pointing to the save mode or the open file always has portrait selected.
Many thanks for your help, at least I can print out my cheques with just a little adjustment.