Newbie - gut instinct or fear?

[Kevin Miehe]

Newbie here ready to make my first investment, a buy & hold rental. I can't tell if my gut is telling me to stay away from this property or it's just fear of taking the plunge.... any insight appreciated

Davenport, IA duplex built in 1910. Lower B or Upper C-class neighborhood. Not on market, seller is a friend of a friend. Seller is downsizing his portfolio due to health concerns. 

Each side currently rented to long-term tenants on M2M lease. Each side is 3 bed / 1 bath. Unit A has been completely updated, Unit B still needs new flooring, fixtures, etc. Could be done to match the other side for about $10K. Unit B has newer forced air furnace, Unit A has an old gravity style furnace, still functional. Estimate $5k to replace when time comes. Neither side has central AC, tenants supply own window units. Separate meters, tenants pay all utilities. Needs new roof in next 2-3 years, probably $5-7k for that.

PP 83,000
Unit A Rent $750 | Unit B Rent $650
Financing through portfolio lending community bank would be 20% down on a 20 year commercial at 4.75% with a 5 year balloon
Estimated Insurance: 975/year
Taxes $2225/year
$100/mo allocated for self-PM, business expenses, etc.
1/12 vacancy rate.
Assuming 10% for maint and 10% for captial (Capital may be a bit low knowing the furnance and roof, raise to 20%?) that puts cash flow at $231/mo for a 3.34 Cap rate and 16.7 COC.

Thanks in advance for any insight from more experienced investors out there!