Chas, lines in/out of cooler are both -12. The 'large' line in pic is also -12 scavenge from pan to pump. Just camera position that has made it appear larger. NZ-oregon- is a timber/tree type out here, probably got a fancy botanical type name that I cannot remember at moment
To save you the stress I could draw up a set of plans if you want to fabricate your own-- need a lathe,mill,drill press etc.