10 years ILR question, URGENT

I came in the country in 2001, but I have just realised my very first passport, which has my 2001 entry stamp inside, is gone missing, been searching everywhere, but still can not find it, will i be able to apply ILR using other form of proof e.g. school letter proving i was in UK at that time or be able to obtain the record from the home office ?
thank you very much
regards
lawerence

Please continue in your previous thread.