+xThis is what what gets us confused, as the spent convictions shouldn’t be taken into account, but then you need 5 years after being released.
This is what I was trying to put across. Immigration is exempt from the Rehabilitation of Offenders Act. There is no such definition of "spent" in that context. It has its own rules and they are allowed to use any information that they want to including "spent" convictions although it has to be proportionate. The Home Office will have access to the Police National Computer, so don't try to hide anything.
On the face of the facts you have presented I would agree with the solicitor that your chances are better than 50% but please take real legal advice from an accredited immigration advisor, not follow comments from the internet, including here. Prior to my "difficulties" I did help support people with immigration issues. I never gave them direct advice.
You can also contact your local MP for issues with the Home Office.