Dead the is a guy outside troy that moved up from Fl. I bought a 20' ladderstand from him. It had a boat seat and shooting rail.It was made from welded electrical conduit and worked great. I had him build a footrest on mine.
Aw, they may be secure enough, but I just can't afford another injury on top of my aches and pains from years of abuse. The ladders I buy were specifically engineered for safety, PJ, not hunting, but we DO slap a little dull gray or brown paint on them after spraying with vinegar and rinsing them for a light acid etching so the paint will halfway stick.
For a 12' single aluminum ladder, you can shop and find them for a little over $100, and you can get single rail aluminum ladders up to 20 feet or more, I guess, all with an OSHA rating.
You can also lash them to the tree and torque down on them at chest level without stressing the ladder very much.
