Nic, use the CENTRE linestyle, but have LTSCALE set in model space at 1. All plotting should be done in Paperspace. Use viewports in Paperspace. In those viewports set the ltscale at 0.1 (for a plot scale of 1:100). Also set PSLTSCALE to 1. That way it will plot correctly, but as you view it in model space it will not look correct. But if you view it through paperspace it will look correct.
Get back to us for more explanations, this really is a tricky area of acad for beginners.