As lenders, well issue a prequal/preapproval letter if we've analyzed your income, assets (bank and brokerage statements to establish that you have the liquidity to afford the down payment, closing costs, and reserves), review credit of the guarantors, review the relevant experience to ensure that we're not throwing our money away on newbies that are wandering around in the dark, and have put together a reasonable plan of attack for the project.

If your using financing the bank requires this.

Emphasize privacy, entertaining opportunities, and flexibility for hosting large family gatherings.

You may want to find a private lender, sell something, etc…The mortgage lates are going to keep you from any bank/mortgage products

I think there are two maybe 3 ways to look at this in my mind.  1) you go into it and bring it all up to modern standards but using that old charm to basically take what is there bring it up to modern standards and rent it out essentially I'm thinking cocktail bar or something trendy like that.2) most banks are on really good centrally located real estate if this is true, then I'd consider it for the dirt, plan to scrape the lot and go vertical with whatever the highest and best use is.3) a kind of combo of the two, if the lot is in a good location and its doable, pull the vaults or other "character pieces" out of the building, scrape the lot, and build whatever is best suited for the site there, but incorporate those historical pieces into the final designs.Is the site near a major retail area? 

Both are great.Hospitable is great for a part time host. 

You might want to check with local credit unions or community banks, as they’re often more flexible with second mortgages. 

I'm on Airbnb and Vrbo, and also Houfy (direct bookings) but have stayed away from Booking .com because of the horror stories from fellow hosts.

@Haiden Welch I'd lean into local banks and credit unions.

No, banks do not allow a seller held second now a days due to risk and new guide line changes.