I need a repair shop/tailor for a gents lambs-leather Jacket.

There may be a way out.

Take it over to one of the people who repair shoes in Doha. Try to find one who is a Pakistani national. There are many of them around and most have been in this field for generations. They can be easily recognized from their attire. They can tell you if they can repair it themselves or get it repaired from one of shops in Doha which they may be aware of. They may even tell you where it could get repaired if they do not wish to take the job. I have stressed on Pakistan as real leather jackets are tailored in Pakistan. It is a major industry in the country and is commonly worn during the cold season.