What's the checklist when buying a second-hand frame? I am buying a second hand frame (Dawes 201 hybrid) build up (first time doing that, so exciting).

I'm paying cash on collection, so can back out if anything looks wrong. What should I look for on the frame to make sure it's up to scratch?.
Best in sunlight. Bring towel so you can wipe it down. Inspect all tubes and welds. Any crack is bad. Some times a surface crack on a weld is OK. Press and pull on the dropouts. Check the bearing surfaces. Take a seat post with you to be sure it will insert.  Ask questions about the history.