Let the old lease roll over month to month.

Practice these answers until they roll off the tongue.

Inspection time rolled around and the Inspector told me I had one of the best units they have seen in a while.

This weekend it rolled off just south of $510.

Review all leases and match them with the rent roll and ledger.

I've been looking at buying RV Parks, Boat Marines and or Mobilome parks, I've read that SBA and HUD do have loan programs in these areas.My question is who do I contact to help get the ball rolling and pre-qualification. 

Old school ledgers and rent rolls written on notebook paper...

I would get the ball rolling with your new PM, onboarding, photos, etc so that once Jan 18th hits they can flip the switch and turn your property live.  

With this being my first apartment deal I am more unsure about underwriting this type of deal and was hoping to get somebody who is more experience in multifamily to look at the proforma, T12 profit and loss, and rent roll to tell me if I'm missing something or to let me know of things that I should be looking out for.

My only backup plan if I can't get verified funds is to assume the worst and to drop my counter offer even lower than my original due to the risk I would be taking on, and then when I do my in person inspection try and guess what rents are fair market for the empty units, and ask as many tenants as I can what they pay in rents monthly.Seller should give you all of his bank statements for the time he owned it, plus the operating financial documents (including rent rolls)that he received when he bought.Then find an apartment broker in the area and find out about rents in the building and in the immediate area.