Give me a little more time to study it. If it’s not real, then some of the indications are good, for example, the period at end and the formation of the letters. The open ‘o’ in garbo shows that she was a little outgoing at the time. The thing that makes me hesitant is the formation of the ‘g’s, they changed over time in her signature. You can compare her early ‘g’ from documents whiche she signed when she was young to later checks signed when she was older.