One more idea:  properties in the 2 to 4 unit range may qualify for FHA loans, which would allow you to put a very minimal down payment. 

I have a couple rentals & I also do fix & flips & I definitely think you should keep your work minimal on this property as long as you’re keeping it a rental. 

Minimal rehab necessary, roof with danosa(good shape), only 1 kitchen to be replaced and 1 bathroom and a paint job

Now there is a online marketplace specifically established to do this while minimizing the impact on the tenants.

If not, it's really just a shot in the dark, and as Max said, $45k isn't going to cover much on 3 units. 

The current rehab costs are minimal as the home is in great shape, so ~3000-4000 range.

Well, okay, I don’t like it and I do minimize my tax footprint.  

@Swati Batra  Depending on how the building was built, sound proofing between units might be minimal. 

You minimize your expenses by paying the mortgage with rent from the one side you're renting out.

Our biggest problem is moisture seepage from the original hand dug basement walls but given the effect on your joists your moisture problems seem excessive.I have no idea of electrical $$ as its tied in with the common area billing but I'm sure its minimal.