There’s no information in the MD land record archives?

of https://vintagetexas.com/blog/archives/19549#:~:text=In%20the%20mid%2D1800s%2C%20the,laid%20fallow%20from%20this%20infestation.

You may get lucky and get a free one, but then again ...they may well archive it for you for FREE.  

., sometimes you luck out and can find proof of the extra unit existing before the introduction of zoning, in the city archives), however it is rare.Usually the issue is that to go up a unit you need to conform to current building code, including lot size and parking, and the lot just isn’t big enough according to current building code.

Warren Buffett has been vocal about this:https://www.latimes.com/archiv...I know someone with a property currently listed for 7.8M that he bought in 1990.

Purchase price: $330,000 Cash invested: $30,000 Currently rezoning for mixed-use: https://www.newhavenindependent.org/index.php/archives/entry/tattoo_parlor_apts/ - taking a 2500 sq ft stand-alone commercial building and converting it to mixed-use building with street-front commercial and rear residential.

Search the BP archives.

A lot of questions are covered in the archives.  

They may even charge you to retrieve them from storage if they've already been archived. 

Others will use it to archive deal analysis.