Rat Bikes! Pub Bikes Beaters! Frankenbikes!

Don't think you can build a rat. A rat becomes what it is over abuse and constant part replacements to keep it running despite failures. Look at sharky's bike, the ultimate rat for the reference. All these parts are becoming rattier and tattier because the owner looks at its purpose only, not the aesthetics. Most of the parts were expensive once, but rusted and got scratched and paint flaked off and shit. And that's what defines a rat.
And if you can't be bothered to look back for his bike, just google it. It's that famous.

I'm with ya here.... I think the main thing is it needs to be well used and this frame fits the bill as it's been used by a track club for the last 20 years and will continue to be ridden alot