Have I correctly used 'at the last part of,' 'consisting of,' and 'including' in the given sentence?

Have I correctly used 'at the last part of,' 'consisting of,' and 'including' in the given sentence? Please help me.

At the last part of the mass officiated by Rev. Fr. Ben Miller, a tribute was given to the alumni of his school who were 70 years old and above, consisting of tertiary, secondary, and elementary graduates, including priests and other religious people.