hi nilsej
i have seen authentication l;etter of a relative from punjab who went to canada. it was also without letter head. it was bearing only official seal n stamp of the transport authority. it was valid there in toronto.
Do not ever bring a authentication letter without letter head, they dont take it. Drive test or service office would not have taken that letter from your relative.
With authentication letter and copy of licence showing experience of 1-2 years or more, they wave the waiting period between G1 to G2 and G. Waiting period is 1 year between G1 to G2 and 8 months between G2 to G. If your driving licence is not in english then get it translate.
I AM REPEATING TO STRESS ON THIS POINT : No letter without letter head is acceptable in Trive test or service ontario office/ Transport Dept, they just dont take it.