Owner Carry Loans - How to structure escrow - what am I missing

[BJ Ralphs]

Hi All! 

Can someone help me with this Owner Carry scenario? How do I structure the escrow or loan. Sellers wants the down payment in their pocket right away. so do I create an escrow that also draws up separate loan docs for the balance  - I want SELLER to continue paying their small mortgage, but give me possession of the property to rehab it and pay them off everything when I finish rehabbing, sell house and escrow closes. Or do I need to pay the mortgage for them like a wrap around? 

Purchase Price $150,000

I put down 10% = $15,000  (They want immediately) - Then I pay seller 10% interest only on the balance amount $135,000 after the property is sold 

They receive $6,750 plus the $135,000 (They already have my down payment of $15,000) Seller nets $156,750 

Seller owes $70,000 with payments of $500 month - do I make this payment for them or let them continue to make it until I pay it off? 

Let me know if I left out any pertinent info. 

THANK YOU -  to any and all who have a moment to think about this. and help out! I'm grateful for the input. 

BJ