Travel Document for returning permanent resident

I was a permanent resident (landed immigrant) living in Ontario for 24 years - returned to UK due to high unemployment in Canada (1992) and have been working in UK until my retirement. My son (Canadian citizen) went to school/university in UK and worked for over 10 years. He is planning to return to live in Ontario. I would like to return to Ontario, having 2 sons and 3 grandchildren living there. I can apply for a Travel document - but would have to request Humanitarian grounds (i.e. have strong ties - children/grandchildren/friends in Canada - left Canada due to high unemplooyment and remained in UK because a 'job in the hand is better than being unemployed'!) - Does anyone have any experience of applying on these grounds - any suggestions that would 'melt hearts' and allow me to return? Otherwise I would have to ask a son to sponsor me - the application form wanted me to fill out all the places I had lived since I was 18 yrs (now 67) and all periods of work (can't remember all dates and addresses) - Do Immigration really need this? Any help /advice would be much appreciated.