The cast of thousands that make your campaign alive don’t all need stat blocks. When they do, the usual way to handle it is to have a number of stock of level 1 characters, and improvise starting from those. But sometimes you do not need a whole stat block, and not every character has an character class.
The alternative is the Simple NPC with a Thousand Faces. The idea is that each person is sort of average, but they have both a Flaw and a Perk, and this lets you flesh them out a bit in the maybe twelve seconds they appear in your game.
The Perk is what they are good at, where they apply the proficiency bonus (or Focus) based on their level, with an additional +1. For example a construction worker is good at building things, demolishing things, and operate heavy machinery: if they are a level 1 character, they get a +3 on those rolls. In general, this is not limited to job skills: it should apply to all they are good at! They should also be good at something completely unrelated to their trade, like a hobby, craft, sport, baking, ikebana, massage, etc.
The Flaw is something negative about them. Determine an ability at random by rolling 1d6, and come up with a negative trait associated to that ability. A Strength Flaw might point to a small build, or a physical impairment like chronic pain, and a low wisdom might suggest someone falling for all jokes, a conspiracy theorist, or someone easily swayed. The Flaw does not imply they have a low stat, but they might if you need them to.
In case they get shot/stabbed, they have 6hp.
Lost Pages 
Hello Paolo! Apparently I’m one of your people, because I was both interested in stealing and amused by your OSR mechanic ruminations, AND because I was moved by your confessions of the difficulties in your life at the time of writing. You’re a natural author, and fooking brilliant at it, IMO.
Google flung me into your site as I searched for a random table of lasting scars. The Flesh/Grit system I found on Cavegirl and Castles and Casuals seems like too much of a stretch for my players, and so I’m playing with the idea of 0 HP as the trigger for a blend between “Bloodied” and “hemorrhaging” that lasts until the actor (PC or NPC) dies or realizes they’re fooked and in need of Stabilizing. I’d love to hear your take on the idea.
Your writing is excellent. I love the things you’ve come up with. Seeing that you haven’t posted here since November makes me sad. I know we’re doing this pandemic thing and all, but I hope you’ll publish more stuff. I’ll see if I can find your publications on DriveThruRpg.
Please know that my first impulse was truly just to share my enjoyment of your work with you. But given the nature of the internet, I gotta leave you with a brief pitch: I’m an illustrator, and I’d love to make OSR drawings for your publications. andrewfearnside.com if you’d like to see my mostly-unrelated-to-OSR work.
I live in Albuquerque, New Mexico. My first taste of The Game was thru the 1979 Basic set, in 1979.