A Question about my credit report?

Me and my husband would like to get a mortgage, i have a bad credit history and my score is classed as "very poor"

After looking at my credit report, (in my maiden name as I am yet to be added to the electoral roll in my married name) half of the bad debt I have isnt showing up. We did move house, which is when my car got repossessed and then moved back to the address we are living at now.

I am guessing that this is the reason that my credit report isnt showing it?

The only thing that is confusing me is that on the linked addresses section of my credit report, my previous address is showing on there, but the debt from that address isnt showing on my profile, is there a reason for this?

I was wondering if it was worth even telling the mortgage company I lived there as it was only a very short period of time and if its not coming up on my credit report who's to know!!??

Thanks in advance