Mortgage HK cash incentive treatment for rental cost base

We have a mortgage in Hongkong through HSBC with a small 'cash incentive' tied to it - i.e., upon closing we got a small amount of money -- which happened years before we moved to the US. When locking in the cost basis for this property now used as a rental - is that cash incentive to be taken into account? E.g., effectively reducing the settlement/closing costs? 

 

Reason I'm bringing this up in particular is that I'm trying to tee up what our CPA did for our cost base lock-in specifically for Settlement & Closing costs. The CPA refuses to provide detailed information on it; and I can simply not reconstruct the number locked in for the purchase price with all the paperwork we provided. Thus, I'm looking through all (partial) amounts of money which had been somewhere in the paperwork and might have been incorporated into that amount. Other ideas could be around prepaid mortgage insurance, fire insurance - which to my understanding should not be in there. 

 

Thank you for any help