I would NEVER disturb a near 100 yer old foundation unless replacing it.

I know of the lead-based paint, but I think if I don't disturb it, and drywall over it it'll be ok.

I haven't walked the interior of the property as the owner does not want to disturb the tenants until an offer is accepted w/ a pre-qual.

Not mention vacant periods for a single property would mean a 50% disturbance vs 33%.

Seller will not let me see the inside of the property, to "not disturb the tenants".

I'm already disturbing tenants with inspections and walk-throughs, so I'd like to avoid having 3 more trips for contractors!

If you haven't already, I would recommend linking-up with a Realtor experienced in small multi-families (MF's) in your area and going to see the units and if the noise will disturb neighbors (possible you can find a light renovation project that won't impede on the baby's schedule)? 

IT is month to month lease, so I think I can raise it once I take over.How can I make an appointment with tenants, the contract stay don't disturb tenants... 

We cannot prove it, however we are quite certain there is plenty of drug activity going on in this apartment, not to mention they are constantly disturbing other tenants with screaming.this property is located in Missouri.

If any paint is disturbed, then it must be dealt with under the assumption that lead paint is present because of the age, and must follow EPA lead paint removal guidelines which are very stringent.