heights of double decker layouts

Hi - I have two different guages, O and HO, running here. space restrictions are suggesting a double decker layout i.e. one guage at one level, then another at another level. Any suggestions on doing this double decker idea? Specifically - which guage to go on top, what heights above finish floor should they be placed, controlling arrangement - i know that my dad had these at double decker arrangment but i totally forget what heights and i was so small then that i probably wouldnt have accurate recall anyway.

…or is the double decker method no good?

Thoughts? thanks!

kb @ S. Ltd

I’d have your O at the bottom, and HO at the top. The HO would be more eye level, so it’d seem bigger just because of how close you are to it, and the O would be a bit farther but it’d still be big because of the contrast of the HO. So, I’d have HO being on the level closest to eye level.