I'm thinking that this is one of the rare Japanese Hercs.<g>
The real question will be, was this a Raleigh-Hercules, or before the take-over. The "H" bracket, the "fifty year frame guarantee" says before, the thimble forks and plain cut-out chain ring say after.
The head badge is a wild card, can't find anything about a Popular with a King Frame
The tubing question was dumb, sorry, this is a "Popular" a run-of-the-mill-roadster. I can weigh it in comparison to my Sport, but I'm not expecting any difference. The earlier Hercules catalogs make quite a bit of their high quality tubes, however.