Fly fishing line and not the floating stuff, nor monofilment (ck spelling) braided Dacron sounds good. It streaches just right and leaves a nice fine line. Also most square rule is based of a reference face and is very precise and from my point of view easy to learn and apply, no need to use mill rule. That is mostly because I use only rough sawn stock. I think even with s4s timber I would still square rule, and that would be a breeze, no wany edges wow!

brad, what do you mean by a full housing? Maybe a 4x6 coming into a 8x8 that is centered and than housed? Tim