Writing an approach letter

I am in the middle of a case study interview, and one of the tasks is to write an approach letter to the CEO of a potential client.

I am wondering if there are any 'must haves' or industry standard that I might not be aware of since this would be my first job in ibanking. Specifically, are there any charts or graphs needed?

My train of thought thus far is to write the letter as if I work for the company, emphasizing the bank's: -core competency of finding takeover target's at good deals in this industry -mention some similar transactions -our competitive advantage -how we have been following this company and have it valued much higher, and think a strategic acquisition will drive realization of this value.

anything missing? much thanks!