Should I invest in this unique multiplex project

[Sam LLoyd]

Here's a project I'm working on.   I'm finishing up my due diligence and getting to the point where I need to make a go/no go decision.

Project:  Detached 7-plex on two lots... I'm financing them as a triplex and fourplex.  Very tiny buildings in a B- or C+ neighborhood... buildings are newer... a solid B.

Term:  Working with the seller such that I'm going to be into the project with only closing costs.  Cash-flow (self-managed) should be around 500/month, with a 60k balloon due in 5 years, after which cash-flow should jump to 1700... if rents stay the same.

Problems:  Still trying to get tax returns to show rent history.  Also, due to the uniqueness, the only exit strategy I can see other than holding them would be to sell them at a loss.  Rents are right at or slightly above what I would have projected from looking at the market.

Thoughts?  Thank you in advance for any input.