Question on deck built---city says no permit taken out.?

Twenty five years ago, we put an additon on our house & a deck.We had a contractor & builidng permits.My husband died during the construction, & I remember little about it as I was finishing school & had 3 children under 5.The city came around last week to reassess my house---they have permits for the addition, but not the deck.I have no paperwork. Although they said they will most likely charge me for two previous years, & not 25, I am still very worried.They are sending someone next week to check that the deck is up to code---my railings are 35" & what I saw on line says they must be 36". I don't know what to do---I am also worried that they may make me pay huge fines or something.My son called and said he could come & put an additional 1" board on top of the existing railing & stain it to match. I am hoping that is enough.They sounded like they are going to make this difficult--the first guy I spoke to said I will have to take it down & pay thousands in back taxes & fines.This is ND