as far as advise goes, make an attempt to get permission to enter any property from someone, weather it's the property owner, caretaker, or a 3rd party. many times you may get shot down but if you explain you would like to preserve the history of the location by gaining access and shooting some photographs it can lead to risk free access or possibly even a tour of the property ( always neat to learn the history from someone who knows it). I know getting permission isin't always an option for exploring many abandoned structures, but without permission to enter I would recommend only looking from the outside.

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2000 XLT 4X4, 3.0, Auto, regular cab - throttle cable mod, K&N drop in filter, taylor thundervolt 8.2 plug wires, autolite sparkplugs, Accel coil pack, AVS Ventshades, Rampage LED tailgate light bar, BFGoodrich All Terrain T/A tires, Trail F/X toolbox, cruse control pod light fix, Cobra 19 ultra II CB, lil wil antenna, pioneer door speakers, expo woodgrain radio bezal, 06+ mirrors & tails, powerdome hood

2000 XLT 4X4 Offroad, 4.0 / auto, supercab - the project truck!

I'm not sure if the intent is to scare the beejeebers outta yourself or to tour and preserve historical buildings and landmarks.
Around here I'd be pissed if I stepped on a needle.

glanced at the Built St. Louis.net site, looks very comprehensive.
I've gone on lots of free city walking tours that are really interesting and no need for a weapon.

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2008 FX4 Ranger. Black/ Black
Undid the full size Mod.
Kept the power rear window
https://m.youtube.com/watch?v=82y5AyI5eEY

Needles would be an issue of concern here.

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2013 Ford Focus SE hatch - My daily driver
2018 Chevy Equinox diesel- Wife's
2001 Ford Ranger XLT 4x4 4.0 Supercab Off-Road Stepside - Bunch of stuff.