You probably can't get that door hardware any more unless you go to an antique place but if there's nothing particularly historical about what you have you can sleeve the entire opening if necessary and add modern door knobs/deadbolts.

Ignore that and just keep dumping TSP in the water until no more will dissolve.The TSP solution will be pretty alkaline... wear gloves (the kind for washing dishes is fine), and long sleeves. 

@Tom MurphyWhy not just roll up your sleeves and rehab it yourself ?

I am buying one for $59k today but it has 26k in rehab and might require me to roll up sleeves and do the demo myself.Why did you decide you wanted to invest in real estate?

The only way to get better at custom deals is practice so I'll roll up my sleeve! 

Although I am new to REI, I am a hard worker and fast learner ready to roll up my sleeves and get to work.

My advice would be roll your sleeves up and search for the park yourself.  

@Michael Baum I’m covered in tattoos and don’t own a shirt with sleeves.

They may leave the jacket in the car but they always have button down long sleeve dress shirt and a tie. 

I'm more than happy to add value however I can in exchange for someone sharing their knowledge; whether that be rolling up my sleeves and doing work on properties or bringing deals!