Rabone Chesterman for me, I bought it when I was an apprentice, lost its paint but still going good, has drawn all my mitres I have cut by hand over the years. I purchased another few years back a smaller version not rabone and is very handy just like the first one for drawing lines but also running lines along edges to a fixed depth if you need a bit more depth than using your index and thumb holding the pencil and long finger your guide. It is also good for pushing in to depth for facing edge truing etc.
Just needs oiling occasionally to prevent rust though my newer one is galvanised finish to blade just a handy size for your pocket or nail belt.
I have the larger Marples type with rosewood in varied sizes but is mostly used in Shop or bench. I have also builders squares in timber made by me done on the faithful 3-4-5 method replaced when required and steel 1m square for roofing though not used much now along with a few steel rules varied lengths for drawing out.
