Addressing two gentleman same letter same last name

[Unregistered]

Mssrs. V
Misters V
Mister and Mister V

[PappaMouse]

Mssrs. V
Misters V
Mister and Mister V

The appropriate is Mssrs. V.

But if you want them to sit up and notice you...say Mister ___ ____ V and Mister ___ ____ V. The extra time it takes to mention them both as individuals goes a long way.