Can Quit Claim be filed post death to avoid tax increase?

grandma passed away years ago. family never probated will. grandma only had the house. she wanted my older brother to remain there. the house was paid off. i've paid utility bills and taxes for the past 20 years. mom (her daughter) and my older brother now both deceased neither left a will. the will and quit claim deed grandma filled out was left in the house in a safe, neither were noterized. i was recently notified by the county tax assessor of an increase in taxes due to a reassessment of property value. this was brought on by them being notified that my grandma had passed away years ago. i'm now facing a big tax bill for the difference in all of past years taxes. is there anything i can do to get the house into my name and transfer title so that the taxes won't increase? the quit claim was made out in my name but never filed. any suggestions?
thanks nan