Judges Guild City States

I've had the Judges Guild's "City State of the World Emperor" set for 30 years or more, and also got a reprint copy of "City State of the Invincible Overlord" 8 or 10 years ago. 

They are very peculiar items.   Every single shop, temple, government building, beggar's lair, garrison company, tavern etc., is given its own paragraph of detail.  Every building has one or more NPC stats given for it.   In "Invincible Overlord" the descriptions are organized by street, in "World Emperor" they are organized by type, and a large blank is left for the GM to put a key number to place on the city map.

Here's an example from "Invincible Overlord":

Locks:

Scopgradon:  FTR LE  lvl 5   HtK 18  AC 9, Soc Lvl: 6, Str 10, Int 12, Wis 15 Dex 5, Con 10, Cha 14

Scopgradon is noted for super-strong locks (18/00 to break) selling for 100-600gp.  50cp and 15sp in cash box, 550gp triple-locked chest in room chained to steel post. (Invincible Overlord p6)

You'll notice that the locksmith is a 5th level fighter.  This is far from unusual.  In both city state books every single NPC has a class and level, and while many are first level, most seem not to be. 

The system seems to have been a late stage of Original D&D, just before AD&D first edition came out.  It uses the 5-fold alignment system (LG, LE, N, CG, CE) found in the Holmes' basic D&D and in the AD&D Monster Manual, but surpassed by the 9 alignments of the AD&D 1e PHB.   Most AD&D classes are present, but they were present here and there in OD&D too.