Securing loans with a low credit score is possible through private or HM lenders.

As others have commented, this is a scenario where you will have most luck with a private individual lender or some other local financing - just too small for pretty much all the national platform hard money lenders

The main reason I'm asking this, is to understand how much cash I need to save up in reserves before pulling the trigger on a deal like this?

Private message me if you need someone local.  

I've committed myself to being a full-time real estate investor, private money broker and real estate consultant!

We still own this property, but we have: 1) leased to market rent, 2) successfully implemented RUBS to save roughly $3,000/year, 3) Reduced vacancy/bad debt from pre-acquisition T-12 of 15% to less than 4%.

The promissory note and personal guaranty are private documents that don't get recorded.

I got started with private money back in 2009 and those were scary times.

Use an operating account for income and expenses, a reserve account for maintenance and taxes, and a high-yield savings account (HYSA) like Capital One's 4% APY for idle funds awaiting reinvestment.

There is short-term savings in replacing my mortgage with my credit line.