https://en.m.wikipedia.org/w/index.php?title=City_of_London_...
Arms: Argent a cross gules, in the first quarter a sword in pale point upwards of the last.
Crest: On a wreath argent and gules a dragon's sinister wing argent charged on the underside with a cross throughout gules.
Supporters: On either side a dragon argent charged on the undersides of the wings with a cross throughout gules.
Ditto police forces: although most smaller authorities' police have merged into larger county or larger forces, there's nothing odd in principle about a municipal police force. The City's is strange, in that it's entirely enclaved within the Met, but there are plenty of oddities out there (the Mersey Tunnels Police, say).
There are several ancient cities with 'Lord' mayors, including York.
Are there some books that comprehensively cover several aspects around the City of London?
The City of London appeared quite often in Lee Kwan Yu's memoirs